THE STELLAR SYSTEM.

The thousands of stars which spangle the heavens are all part of one "system;" but it has been found by the aid of the telescope that this system is but one out of many. Our system of stars occupies a space somewhat in the form of a thick lens or much-flattened sphere, but others are of very different forms, and some have but little regularity of form at all; our sun is one of the stars of this system. It is not known whether there are planets revolving round the other stars, the distance being far too great for any telescope to render them visible. Our sun occupies a somewhat central position in the system. The stars are classed into sizes, as first magnitude, second magnitude, &c., on to the thirteenth or fourteenth magnitude, but all beyond the fifth magnitude (by far the greater number) are only visible by the aid of the telescope. There are about 5000 stars visible to the naked eye. But fourteen stars of the first magnitude are in our hemisphere of the heavens, and about fifty of the second, but the number of stars of each magnitude increases prodigiously in the higher numbers, so that those stars capable only of being seen by the aid of powerful telescopes, amount to many millions; these are chiefly situated in a great belt which encircles the heavens, called the "Milky Way," which is caused by the line of vision passing through the breadth of our starry system, and consequently meeting with a greater number of stars than in other directions, where it only crosses its thickness.

The other systems of stars, called "nebulæ," from their resemblance to little clouds, were supposed to consist of luminous matter of but little density, and which might at some future period be condensed into stars; but the improved power and construction of telescopes have enabled astronomers to resolve many of these nebulæ into clusters of stars, and there is but little doubt that all could be thus resolved, were the telescope of sufficient power; and thus it appears that in the infinity of space collections of systems are placed, each one too distant from the others to be calculated or written in numbers, but each consisting of thousands of suns many hundred times greater than this earth, and many millions of miles from each other. What an idea of space does this afford, and how soon do all our narrow notions of possibility and impossibility vanish before such facts accomplished by the hands of God!

FIG. 24.

FIG. 25.

Amongst the stars composing our system there are certain conspicuous groups or constellations, which were named by the earliest astronomers, and compose a list of the most ridiculous imaginary figures, as useless to the casual observer of the stars as to the astronomer, and have not the most distant resemblance to the figures after which they are named, as for instance the "Great Bear" (Ursa Major) fig. 24. The grouping of stars into constellations serves, however, to find any one required (provided the groups on the chart can be identified with those in the heavens), as for instance the three conspicuous stars forming "Orion's belt" (fig. 25), from which a line produced eastward will point to Sirius, the brightest star in the heavens, and another line produced westward will serve to point out "Aldebaran," also a star of the first magnitude, &c.; also a line drawn from a to b in the Great Bear will nearly point to the pole-star—the star situated nearly (although not exactly) at the pole, or that part of the heavens which would be indicated by a line drawn through the earth at its axis of rotation. Amongst the stars scattered over the vault of heaven there are many which to the naked eye appear single, but which when seen through the telescope prove to be two stars closely approaching each other. These "double stars" are of two kinds, "optical" and "physical;" optical double stars are those which appear to be near each other merely from the accident of one being placed behind the other, nearly in a straight line, although in reality at an immense distance and in no way connected. Physical double stars (usually called "binary systems") consist of two suns comparatively near each other and revolving about their common centre of gravity. Sir William Herschell first discovered their physical connection, and thereby proved that the great law of gravitation was not confined to our system, but was the ruling power which controlled and regulated other systems. Astronomers have calculated the orbits of only fourteen such "binary systems" at present with any degree of certainty; about a thousand double stars are known, but only about one hundred "binary systems." In some "binary systems" the two suns are of different colours; white and purple, red and green, or yellow and blue. If any planets revolve about such suns, when situated between the two, what strange phenomena must occur! Imagine a day during which a red sun had tinted everything crimson, being succeeded at sunset (not, as with us, by darkness) by the rising of a green sun, changing the colour of every object from red to green, and how curious and beautiful must be the shades of light and colour during the transition from one day to the other. Can anything be conceived more gorgeous?—no shadow, but every object tinted with a combination of colours of the most brilliant hues! Triple, quadruple, and multiple stars are known in abundance, but all probably optically so, and not in any way connected with each other by attraction. Others of the stars are called "variable," they are those whose light gradually diminishes and after a time regains its former brightness; some of them not only vary in brilliancy but in colour; the cause of these phenomena is totally unknown, and fortunate will he be who discovers it; it will be a great stride in the science of astronomy, for at present everything proposed has been quite inadequate to account for such phenomena. About 60 of these variable stars are at present known, but others are constantly being added to the list. Hind has discovered twenty-one, Pogson seven, and other astronomers have taken their share in discerning them.

But, of all the heavenly bodies, none have excited so much wonder, and in former times so much fear, as the Comets. The orbits of these are for the most part in very eccentric ellipses, some of them comprised within the limits of our solar system, while those of others extend millions of miles beyond it, so that they only reappear to us after hundreds of years. The matter of which these bodies is composed is certainly not solid, as the smallest telescopic stars may be seen through the very middle of it, although many thousand miles in thickness. When comets approach the sun, their substance appears to become more condensed, and therefore to possess a greater power of reflecting light. The cause of the "tails" which appear appended to comets when they approach the sun is not known, but this tail extends always in a direction from the sun, and passes over many degrees of the heavens' space. As comets obey strictly the law of gravitation, they must possess some amount of weight or mass, however small it may be, and that it is inconceivably small is proved by the fact of comets having passed close to Jupiter, right amongst his four moons, without in any way affecting or disturbing their well-known motions; the comets have, however, been terribly tossed about on such occasions, one having been totally lost to us by such an occurrence.

Thus it is seen how the same laws of gravity exist throughout all the infinity of space. The comets traverse our system of suns, and passing onwards with incredible rapidity, for years upon years, through that great space beyond it, at last visit some other system—perhaps to be as much an object of regard and wonderment there as they were here. The same ray of light which emanated from one of the distant stars of some one of the clusters situated far out in space, and which has travelled for thousands of years at the rate of 200,000 miles for every second of time, serves us here on this globe to distinguish it—it enters the tube of our telescope and affects our optic nerve; and the Creator who caused it there to be given off, has here made our senses capable of perceiving it. Is not this a clear demonstration of the fact, that one hand has designed the whole; and one Creator provided for all?

[THE AIR.]

FIG. 2. STORM, WITH HEAVY RAIN.

FIG. 1.

The earth is surrounded in all directions by a covering of air about forty miles in thickness, which bears about the proportion to the earth itself that a coating one inch thick would to a ball seventeen feet through, being about 1/200th of its diameter. This air, though invisible, may at all times be felt while in motion (such is the wind), and by rapidly passing the hand backwards and forwards it may be perceived to press against and slightly obstruct it; this air is composed of about twenty parts oxygen and eighty parts nitrogen, together with about one part in every thousand of carbonic acid (consisting of carbon and oxygen in union) and a small proportion of vapour of carbonate of ammonia (ammonia in union with carbonic acid). It is the oxygen which enables animals to live in the air, as it is taken into their systems at every breath, it is thus constantly being consumed and would ultimately be so far diminished, that they could live no longer for want of it; but Providence has so arranged, that the necessary quantity is always being supplied by vegetables (which give out oxygen) to meet the deficiency. The air, although a gas, is yet capable of being weighed, of great compressibility, and of expansion to an unlimited extent, this causes the lower part (near the surface of the earth) to be much more dense than the upper regions, and those who have ascended to the tops of high mountains, have described the difficulty of respiration as being very great, owing to the rarefaction or lightness of the air. At the surface of the earth it presses with a weight of about fifteen pounds upon every square inch, but as this pressure is equal in every direction, it is not felt by us, nor does it crush the most fragile flower or insect; but, remove the pressure from one side of anything, and it will be found to press with violence upon the other. If the air were removed from the inside of a drum, the weight of the surrounding air would burst in the parchment and fill it. By way of experiment, fill a large basin with water, take a tumbler in the left hand and a piece of lighted paper in the right, hold the lighted paper for a moment under the inverted tumbler and immediately apply its open mouth to the surface of the water, letting it dip in about half an inch, the heat expands and consequently gets rid of some of the air in the tumbler, and as this cools again it resumes its original bulk; the pressure of the air on the surface of the water in the basin will force it up into the tumbler and nearly fill it (fig. 1). This is the principle of the barometer, which is a tube entirely exhausted of air and the weight of the atmosphere forces a column of mercury (which is many times heavier than water) up to the height of about twenty-nine inches, according to the weight of the air at any particular time; this weight varies according to the state of the weather, whether wet or dry; but the average weight of air is found to be perfectly stationary, and during the twenty years from 1816 to 1836, it was found at Paris not to have varied 1/1200th of an inch. Winds or currents of air proceed from several causes; when the sun shines on a large surface of the earth, it becomes heated and a column of hot air is pressed upwards, for hot air is lighter than cold, and the cold air all around, by its weight, forces it up and rushes in to fill the space; this space may perhaps be many hundred square miles in extent, so that a current of wind is caused to blow towards this spot from all the regions round. This is the general state of things at the equatorial parts of the earth and causes the "trade winds," which uniformly blow (the greater part of the year) from both north and south towards the equator. Another cause of local winds, is the condensation of vapours into water; when the air over a large region is saturated with moisture it is greatly expanded by it, and when the vapour is condensed and falls as rain, the air from the surrounding parts forces itself in to fill the space occupied by the rain while in a state of vapour, which is nearly one hundred thousand times greater than it occupies when in the form of water. There are many causes to determine the condensation of the vapour, which the atmosphere always holds in larger or smaller quantities, but cold is the chief agent, for when a current of air passes over seas or rivers, or the damp surface of the earth, it becomes loaded with moisture, and being capable of holding only a certain quantity (less when cold than hot), it follows that warm air when saturated with moisture must let some of it fall when it becomes cooled. This may occur from entering a colder region, or uniting with another current of air colder than itself. In tropical regions the air is so warm that it takes up a very large quantity of watery vapour and upon the coming of colder weather, the rainy season begins and the air empties itself of its superfluous moisture, causing the most tremendous falls of rain in consequence (fig. 2). When the clouds are overcharged with moisture in cold climates or in cold weather, the vapour freezes as it condenses and forms snow, which under the microscope presents a series of the most beautiful star-like crystals (fig. 3); the same result is produced by the freezing of the vapour or fog near to the earth's surface, this is called "hoar-frost," which is (like dew) deposited on those parts of the surface most cooled by radiation. Hail is caused in all probability by the drops of rain passing through a cold stratum of air and becoming frozen as they fall. There are many wonderful accounts on record of great masses of ice falling from the clouds, some of them several feet thick; the cause of these phenomena (if they ever did occur) is not known. The curious occurrence of red or green snow, which has sometimes been known to fall, is owing to the snow being mixed with myriads of minute cellular plants called the Protococcus pluvialis, which in one state of its existence is green and in another red, and they colour the snow accordingly. The cause of their sudden accumulation in such vast quantities is not known, but may be sought for in some peculiar state of the atmosphere favourable to their growth, which in many places is prodigiously rapid.

FIG. 3.

The temperature of the air differs very greatly in different situations at the surface of the earth, the extreme difference being about 180 degrees; thus in winter, at the poles, the thermometer frequently stands at 60 degrees below zero, and at the equator, in summer, 120 degrees above, but, in the higher regions of the air, it is even colder than at the poles, for the sun shining on the earth heats it, and the air is heated by contact with it; this is its only source of heat, of which it receives less and less the further it is from the earth, so that at a distance (depending upon the situation and climate) ranging from 3,500 to 17,000 feet from the surface, the air is so cold that it is called "the region of perpetual snow," and all mountains whose tops reach above this altitude are covered with snow (formed by the freezing of the rain and vapour) from this point to their summits (fig. 4), and the sun (although it nearly always shines there, these regions being above most of the clouds) is not able to melt it, for the radiation of heat from its surface is greater than its absorption from the sun's rays, white substances absorbing but very slowly, and rough surfaces (as the snow) radiating very rapidly.

FIG. 4.

Dew is caused by condensation of the watery vapour held in the air; when the sun goes down the radiation continues from the surface of the earth, and those surfaces which radiate most rapidly, such as fields of grass, get cooled down below the temperature of the surrounding air, and therefore cause a condensation of its watery vapour. This may be imitated by filling a large glass goblet with very cold water, and bringing it into a very warm room, the outside of the glass vessel will become covered with dew, although previously quite dry; the same may be shown by filling a similar glass with water at the ordinary temperature, taking care that the outside is dry, then stirring in an ounce or so of nitre or Rochelle salt, which will cause the water to become cold, and the outside of the glass to be covered, as before, with dew. Dew falls fastest when there are no clouds in the sky, as radiation then takes place from the earth into space, and is not compensated for by a return of radiation from the clouds to the earth.

FIG. 5.

FIG. 6.

Clouds are formed by the partial condensation of vapour, and are borne along by the wind, instead of falling as rain; the reason of their not falling is this, when the air below the clouds is saturated with moisture it will absorb no more and the rain falls, but when it is warm and dry, and passed in a constantly renewed current, then the vapour is absorbed before it reaches the earth, and is carried off by the wind. Clouds, therefore, although they often appear stationary, are constantly altering their form and size, portions being absorbed while others are being formed. Fogs are the same as clouds, the vapour arising from wet grass, rivers, &c., being condensed as it ascends, by a current of cold air passing over them. The fogs in London have a brown colour, from admixture of smoke, dust, &c., with which the air is contaminated (fig. 5). Clouds are of various forms and sizes, and indeed of almost every variety, but certain kinds which are frequently seen, have received different names. The "cirrhus" comprises all the feathery white clouds which float high up in the air in fine weather; the "cumulus" consists of the large mountain-like clouds which are generally seen in summer; the "stratus," those horizontal layers of clouds low down in the horizon, so often seen at sunset; and the "nimbus" is the rain-cloud, of a dark grey or leaden hue, with sharp well-marked edges (fig. 6).

FIG. 7.

Clouds are amongst the most beautiful as well as useful things in nature, and it is one of the greatest proofs of the active benevolence of God, that all those things which serve man the most, are the most beautiful to contemplate. Without clouds there would be no rain, and without this no vegetation. In many parts of the tropical regions there is little or no rain, and in such parts desert places abound. Clouds are often of different states of electricity, and when they come near enough to each other, a transfer of the fluid takes place, accompanied with a flash of lightning (fig. 7) and a report, although this is not always heard at the same time that the lightning is seen, as sound does not travel nearly so fast as light; there is no danger from this kind of lightning. But it sometimes happens that a cloud in an opposite state of electricity to the surface of the earth is near enough to produce a flash of lightning between them, in this case it is extremely dangerous to be near; but when the thunder is not heard till some time after the flash is seen, there can be no danger, as it is then far away. Sound travels at about eleven hundred feet per second, therefore (in round numbers) it may be known that the lightning is one mile distant for every five seconds that elapse between the flash and the thunder. The notion which prevails that iron and steel attract lightning is entirely erroneous, they do not even conduct it so well as copper and many other metals.

FIG. 8.

Lightning conductors (fig. 8) are wires of iron or copper, made to project above the highest parts of buildings and carried down to the earth; they have the power of conducting the lightning down without injury to the building, for electricity (which lightning is) travels through metallic wires for any distance without disturbance or noise (as in the electric telegraph), but bad conductors are apt to be burst and rent by it if it be strong enough, creating flashes of light and reports. Lightning strikes most readily any projecting substance or point, the highest point is therefore selected for the protrusion of the upper part of conductors. In a plain or open space, trees and animals are often struck, as they form conductors (although very bad ones) to the lightning; being bad conductors, instead of allowing it to pass quietly to the earth as do the wires, they are generally destroyed by it. It has been often stated that we should select an open space in a thunder-storm, but this would render one liable to be struck, especially if there were no object near of larger dimensions, the best plan is to stand near to any trees or houses without touching them, the danger would not then be so great, the trees or buildings being taller, would be most liable to conduct the lightning to the earth. The danger of touching or leaning against a tree in a thunder-storm, arises from the person thus making himself (as it were) part of it and incurring the same risk.

Thunder-storms, which would at first thought appear to be of no utility to man, are indeed of great service; it is a common saying that thunder clears the air, this is the result of feeling and experience, but chemists have demonstrated the fact that a substance called "ozone" (a peculiar state of the element oxygen) is produced by thunder-storms; this ozone possesses the wonderful power of correcting (decomposing) putrid and unwholesome gases and exhalations which might otherwise produce fever, cholera, &c., it moreover destroys the ova or germs of many animals and vegetables which might otherwise be injurious to vegetation of more importance, the slight injury which these storms inflict here and there should weigh as nothing in the balance of utility with such universal good. Thus it is that the works of God have all the stamps of goodness, and this ought to inspire us with so much thankfulness as to overcome every fear for personal safety. Were these grand phenomena of nature, (as materialists would make us believe) the result of laws depending solely upon the physical co-operation of mere matter, good would be the exception instead of the rule, and most of them would produce effects, if not injurious at least not beneficial, but such is not the case, and throughout all the wonderful operations of nature there is not one but tends to good, for God often inflicts a small injury that a great good may result; we say a small injury, but it is questionable if the injury is not often a benefit, which appears to us injurious only because we do not understand it fully, every disturbing cause tends to produce some apparent disorder, such as storms, hurricanes, &c., some indeed so terrific as to destroy ships and houses, but what would be the result if the atmosphere were never disturbed from any cause? Why the lower stratum would become so loaded with impurities that it would be unfit to breathe, miasms and noxious gases would for ever remain a curse to the races of men and animals who might be doomed to inhabit such regions, but the very regions where these miasms are most likely to form are those about the tropics, and here it is that the greatest storms occur to remove them. Even the great deserts, which appear so useless to man, and which are uninhabitable to a great extent, have their office, and an important one too; they are to the earth what ventilators are to buildings, drawing the cold air from the poles to cool the regions that are too hot, and sending a current of heated air through the upper regions of the atmosphere (where it can do no injury to anything) to warm the colder parts of the earth, another instance of the wonderful care and goodness on the part of the Creator. The various and beautiful colours of the clouds, particularly at the rising and setting of the sun, are caused by refraction separating the white light into its primitive constituents, blue, red, and yellow light and their combinations, purple, orange, green, &c., and the more obliquely the rays impinge upon the earth the greater will be this refraction, this accounts for colours seldom appearing in the clouds at midday. But of all the beautiful effects of the refraction of light, the Rainbow (fig. 9) is the most glorious, it has been celebrated in all ages for its transient beauty. It is only seen when rain is falling in front of a brightly illuminated cloud, the sun being behind the spectator; it is a reflection of the sun by the cloud transmitted through millions of drops of rain, each of which acts as a prism, and produces rings of colour; for each of the rays of light (red, blue, and yellow) are refracted in unequal degrees, and therefore take separate places, forming the rings of colour seen in the rainbow.

FIG. 9.

The air is the great source from which all the nourishment of the organic creation, whether vegetable or animal, is derived; its carbonic acid is decomposed by the vegetables, which appropriate the carbon, turning over the oxygen to their companions, the animals; the ammonia of the air furnishes all the nitrogen of seeds and other nutritious parts of vegetables, which are eaten by animals; and water, the chief source of all nutriment, passes first from the air before it enters the soil, bringing both carbonic acid and ammonia to fertilise it. That all this nourishment is derived from the air is evidently shown by the formation and increase of mould in forests which have grown for centuries; this black mould is nearly all decayed vegetable matter, formed by the continuous fall and decay of leaves and trees, but which, instead of diminishing, increases. Now, where does all this come from? certainly not out of the earth, for it does not contain the necessary elements. Expose the surface of the bare earth for several centuries, and first small plants, then larger ones, will grow upon it, until the state of things described above takes place, the earth being just as rich in organic matter now as at the beginning, and much richer on the surface, where a thick stratum of black mould forms from the repeated fall and decay of leaves and wood; all the substance which the forest shall have drawn from the earth (with the exception of certain salts and earthy matters) must therefore have been derived from the air, which contains every ingredient necessary for its formation, while in the earth itself no kind of organic matter is ever found.

There was formerly a time when the carbonic acid of the air was in much greater abundance, and favoured the growth of those plants which thrive where there is plenty of water, as in swamps and marshes. They grew and decayed for a vast period of time, till a thick stratum of carbonaceous matter was deposited, which, after being buried (by some convulsion of nature) at a great depth, and pressed by the enormous weight of the superincumbent earth into a hard solid substance, is now being dug up by man, and forms that most valuable of all products of the mine, coal (fig. 10).

FIG. 10.

That coal is derived from decayed and altered vegetable matters, is pretty well proved; for many pieces of coal, if ground thin and subjected to the microscope, present a texture exactly such as can be seen in wood of the present date, and not only the ordinary structure, but in very many cases certain "dotted fibres," indicating that the wood belonged to the order of cone-bearing trees (Coniferæ), and there is but little doubt that the constant deposit of such wood and its slow and gradual decay was the real source of all our coal. How wonderful, and how good, is the foreknowledge of God! Just at a time when the great forests of the earth are fast disappearing, and with them the only other source of fuel for fires, this reserve of the old forests, which was then useless, serves man as a most excellent friend—more useful than gold or silver, more precious than diamonds or rubies! But this world is one of perpetual change, and the coal thus brought forth from the depths of the earth, is by man being rapidly restored to the air from whence—thousands of years ago—it was derived; and it is not coal alone which is thus being restored, but every organic being in the whole creation, for at their decay they all enter this vast mausoleum of the dead!

[THE EARTH.]

The Earth, considered as one of those spheres which circulate round the sun amidst the wide expanse of the firmanent, holds but an insignificant position among them, especially when compared with those great and magnificent orbs, Jupiter and Saturn; but, in another point of view, as the dwelling-place of all the animated beings, vegetables, and minerals, with which we have any practical knowledge, it holds to us a position in creation far above all the others.

It is upon the surface of this our earth that we behold in detail those wonders of the Great Creator's hands, which must fill all who contemplate and study them with enlarged ideas of His wisdom, goodness, and power. We see the millions of stars sparkling in the abyss of space, and our minds are so formed that we can measure and gauge their distances and rates of travelling, their orbits and their sizes, their weights, and the powers with which they attract and influence each other; but we only contemplate a star as one bright and beautiful object worthy to be one of the gems which the Almighty has set in His crown of glory, or a lamp to light the halls of His infinite habitation, but we still contemplate it as a single object; while on the surface of the earth our Maker has permitted us to roam and search out by what benevolent contrivances He has suited all things to the comfort and welfare of His creatures. How His mercy and goodness are extended amply to the most minute animalcule as well as to man, and how His powers of construction are to be found in the most minute objects which the microscope can display, as perfect as in the largest creature we behold. It is here upon our earth that we perceive how the structure and functions of all creatures are regulated and controlled by the unerring laws which He has created, over which laws the creatures have no control, and which if duly regarded and used according to the faculties each has been gifted with, will return the greatest joy and happiness their several natures are capable of, and secure all that perfection of operation which their mechanical frames are suited to perform; but before any description of the organised beings which dwell on the earth can be given, it will be proper to enter into a description of the earth itself, to see what sort of place God has provided for them, and how through succeeding cycles of time He has gradually perfected and prepared it for the reception of His last great work, Man.

It is only a few miles below the surface of the earth that man has been able to penetrate and examine, but reason comes to assist him where examination fails, and it would have been but a few hundred yards only that his labours could have extended had it not been that parts, which are generally situated miles below the surface, are occasionally found at or even raised above it, by some disturbing cause which operated in times far back; so that man is able to examine on the surface parts which he could scarcely dig down to.

The whole of the earth, its inhabitants, the air which surrounds it, the waters upon its surface, and its vegetable products, are composed of certain substances called elements, combined and united in certain numbers and proportions. The following is a list of all known:—

METALLIC ELEMENTS.
Aluminium13.7Nickel29.6
Antimony12.9Niobium*
Arsenic75Norium*
Barium68.5Osmium99.6
Bismuth21.3Palladium53.3
Cadmium56Pelopium*
Calcium20Platinum98.7
Cerium47Potassium39.2
Chromium26.7Rhodium52.2
Cobalt29.5Ruthenium52.2
Copper31.7Silicon21.3
Didymium*Silver108.1
Donarium*Sodium23
Erbium*Strontium43.8
Glucinium*Tantalium184
Gold197Tellurium64.2
Ilmenium*Terbinum*
Iridium99Thorium59.6
Iron28Tin59
Lanthanium*Titanium25
Lead103.7Tungsten95
Lithium6.5Uranium60
Magnesium12.2Vanadium68.6
Manganese27.6Yttrium32.2
Mercury100Zinc32.6
Molybdenum46Zirconium22.4
NON-METALLIC ELEMENTS.
Boron10.9Iodine127.1
Bromine80Nitrogen14
Carbon6Oxygen8
Chlorine35Phosphorus32
Fluorine18.9Sulphur16
Hydrogen1Selenium39.5

By this list it will be perceived that the greatest number of the elements are metals, but most of these are very rare and met with but in certain localities, making up but a very insignificant part of the earth's surface, while others (never found in nature, as metals) in combination with oxygen forming "earths" compose the greater part of its bulk. But of all the elements, oxygen (a gas) is the most widely diffused, and constitutes rather more than one half of the whole earth, thus it forms 1/5th of the air, 9/10ths of the water, of the various earths and rocks about 1/2, and in all organised beings about 3/4.

Of the metallic elements, those which form the greater bulk of the earth are—

Silicon.
Aluminium.
Calcium.
Magnesium.
Potassium.
Sodium.

These never exist in nature as metals, but combined with oxygen forming the following earths and alkalies:—

Silica }
Alumina } Earths.
Lime }
Magnesia }
Potassa } Alkalies.
Soda }

These four "earths" form about eighty-five per cent. of the whole bulk of this globe, the remainder being made up of water (composed of eight parts oxygen and one part hydrogen), of "salt," both as rock or crystal-salt, and dissolved in the water of the sea, of the ores of different metals (metals in union with oxygen, sulphur, &c.), and of the remains of former vegetation, existing as coal.

Silica is composed of 21.3 parts of silicon with 24 of oxygen, it is that earth which constitutes a great part of almost every soil, and forms sand, sandstone, and flint, it enters largely also into the formation of granite and the other primitive rocks; when pure it is called "quartz" or "rock-crystal" and is often found in large and beautiful masses. Silica, in different forms, contaminated and coloured by different metallic oxides, &c., forms that class of stones known as "agate," "Scotch pebble," "carnelian," &c., and in the form of flint is found nearly pure, forming "nodules" or rounded masses lying in layers in the chalk cliffs on our coasts, the origin of these nodules of flint is very obscure, but they are by many attributed to the petrifaction of sponges, &c., the general form of which they often retain as well as their internal structure, which may be seen when viewed in thin slices by means of the microscope. Pure silica is a white insoluble powder, and is much used by the makers of porcelain to mix with their other ingredients.

Alumina consists of 41.1 parts of aluminium in combination with 24 parts of oxygen, it is the earth which forms the basis of all clays, loams, and slates, it is in its pure state perfectly white but in most clays is coloured brown or blueish by oxide of iron, many of our most beautiful gems, as the ruby, sapphire, and emerald, consist chiefly of crystallised alumina coloured by oxide of iron, chromium, &c., this earth like silica enters largely into the composition of the primitive rocks.

Lime is another of the earths which form a great part of all soils; it consists of 20 parts calcium with 8 of oxygen. Unlike the two preceding earths, it exists only in union with some acid. When united to carbonic acid it forms limestone, chalk, marble, &c., and when in a crystallised state "Iceland spar." The various kinds of limestone are largely used as building-stones, and any of them when burnt yields lime or "quick-lime" as it is generally called, which is capable of uniting with a certain portion of water, giving out a considerable amount of heat during the combination. Lime is often found in union with sulphuric acid, forming gypsum or Plaster of Paris, in combination with phosphoric acid it forms the basis or earthy part of the bones of animals, and is found in some of the tissues of plants.

Potassa consists of 39.2 parts potassium in union with 8 oxygen, it constitutes about 12 per cent. of the granites and basalts (primitive rocks) in union with silica and alumina, it is also found in the fluids of many vegetables in union with carbonic, oxalic, and other acids.

Soda consists of twenty-three parts sodium with eight oxygen, it however does not exist in this form in nature, but in union with chlorine instead of oxygen, constituting chloride of sodium or common salt, this substance forms strata of considerable extent in some localities and being soluble has no doubt been washed out by the rains from many other places and has thus communicated saltness to the waters of the ocean. The other metallic elements exist chiefly in those forms of earth called "ores" being metals in union with oxygen, sulphur, &c., or are found in the metallic state, as gold, platinum, &c., it is from these ores that most of our useful metals are procured by the process called smelting, as in the case of iron, copper, lead, tin, &c. All the substances known result from the combinations of the elements, but these elements do not chemically combine in all proportions, but in certain definite quantities only; these quantities or proportions are signified by the numbers attached to each element in the list given,[1] and the union of these substances must be in the proportion of these numbers (or multiples of them) only, all superfluity of the substances combined remaining in a state of mere mechanical mixture. For example, if six parts of carbon (charcoal) made red-hot be plunged into a jar containing twenty parts of oxygen, it will unite with sixteen parts only of the oxygen (a multiple of eight), and form twenty-two parts of carbonic acid, the extra four parts of oxygen still remaining as oxygen mixed with the carbonic acid; and if into this carbonic acid twenty parts of lime be put, it will unite with the twenty-two of carbonic acid, forming forty-two of carbonate of lime, still leaving the four parts of oxygen untouched. Had forty parts of lime been put into the mixture, instead of twenty, still only forty-two of carbonate of lime would have been formed, and the other twenty parts (like the four of oxygen) being superfluous, would still have remained as lime, mixed with the carbonate of lime. These combining quantities are called the "equivalents" of the substances.

[1] See the list of the elements at [page 45]; those which are distinguished by an asterisk, are elements of which the "equivalents" are not known.

Upon examining various portions of the earth's surface, they will be found to differ in character from each other; in one place perhaps sandy soil will be found, in another, hard rock, in a third, clay, in a fourth, chalk, and so on. Now, if this examination were carried no further, it might well be presumed that each of these kinds of soil were continued downwards into the earth for an indefinite distance, but upon digging (as in sinking a shaft or well) it is found that the stratum of soil upon the surface is soon passed through, that others in succession present themselves and that this succession of strata is not a matter of chance, but (with certain restrictions) follows in invariable order. It is true some strata are occasionally not present, and that others replace them; but yet (taken altogether) there is the same order of succession everywhere found. The following diagram (fig. 1) gives the section of these strata from the earth's surface to the granite which is the lowest of all formations and through which no one has ever penetrated. The figures give an approximation to their average thickness in feet. These strata do not all run in a direction parallel to the surface of the earth, or else it would result that the surface would everywhere be made up of the highest, but they have been contorted and heaved up into mounds or depressed; and the granite has often been pushed upwards, carrying with it all the upper strata to a certain extent, at last thrusting quite through them all and presenting itself above the surface, forming in this way the tops of many very high mountains, Mont Blanc for instance. Such a mountain if cleft from the summit to the base would present a section similar to that shown in fig. 2, and thus it occurs (contrary to what would at first thought be supposed) that the highest ground is generally formed of the lowest strata, while the valleys are nearly always covered with the latest formations, which is partly owing to the elevating process before alluded to, and partly to the winds, rains, &c., tending to carry away and wash down every kind of soil from the upper ground and deposit it in the lower.

FIG. 1.—DIAGRAM SHOWING THE POSITIONS AND RELATIVE THICKNESSES OF THE STRATA.

FIG. 2.

FIG. 3.

FIG. 4.

FIG. 5.

Fig. 3 represents strata in a state called by geologists "conformable," which name is applied when the strata follow their natural or regular succession, whether this retains its horizontal position, or, as in fig. 4, assumes a position more or less vertical, which frequently happens from the subsidence of one part or the elevation of another; but they are sometimes found in the state represented in fig. 5, and in which they are said to be "unconformable." Such strata after having been tilted out of the horizontal have had other strata deposited upon them, which again may be more or less contorted from the same causes. The regularity of strata is often interrupted by what are called "faults" or "dykes," which have arisen from some part of the earth sinking down or another part being raised up, producing a fracture through all the strata and causing those on either side of this fault or fracture to occupy a situation not corresponding to those on the opposite, as in fig. 6, but yet to be found at a higher or lower elevation, and it is nearly always found that these strata are raised on that side to which the line of fracture inclines, as in the figure. These faults are often sources of great annoyance to the miner, who finds a sudden termination to the seam of coal or ore that he is working. The cracks are generally filled with some primitive rock, as basalt, rising from beneath while in a liquid state and filling up the interstices; it will often happen that the faults thus filled will have veins of the same rock branching out and not only filling up cracks but forcing its way between the various strata, thus interposing a stratum of basalt quite out of its proper position and altering, by the effects of the heat communicated, the character of the strata in juxtaposition; this is shown in fig. 7.

FIG. 6.

Upon a close examination of the various strata which form the crust of the earth, it is found that each has its own peculiar character; some have resulted from the accumulation of matters deposited at the bottom of ancient seas, others in the beds of rivers or fresh-water lakes, or again others (as the coal formation) from the accumulation of vegetable matters; further, these strata do not only differ in structure and composition, but also in the remains of animals and plants found in them; for there is scarcely any kind of soil (above the primary rocks) in which abundant remains of these have not been found. It will now be proper to give a description of them in succession, beginning at the lowest or primary, granite.

FIG. 7.

This appears to be the result of the cooling and crystallisation of that molten mass which many circumstances (hereafter to be mentioned) point out as making up the great body of the earth. Granite differs, in various places, in colour and quality (the varieties are known as "sienite," "porphyry," "greenstone," &c.), but still retains its own distinctive characters; it is a hard, crystalline rock, consisting of "felspar," "mica," and "quartz," in separate crystals, but mechanically blended; its chemical composition as a whole is silica, alumina, and potassa, with small quantities of lime and oxide of iron. This granite is met with everywhere, if the outer crust of the earth be penetrated to a sufficient depth; it however frequently exists on the surface, having no strata below it, and in some places overlies other strata—this, and the fact that cracks and crevices of some of the lower strata are filled up with granite, which could only have taken place while it was in a liquid state, as in fig. 8, together with evidences of the effects of calcination, and other changes producible only by extreme heat, all around those parts and in the strata immediately overlaying the granite, point out that it was once in a state of fusion.

Above the granite formation, in many places, especially in Norway and Sweden, there is a stratum of rock called gneiss, which consists of the same ingredients as granite in a slightly altered form. Granite will often pass into gneiss gradually, and this again into those slaty formations which rest upon it and come next in the series. These consist of mica-slate, hornblend-slate, and chlorite-slate or schist, a name given to all those rocks of a slaty structure which have a cleavage or capability of being cleft into thin laminæ or slices (hence their applicability to the purposes of building, forming excellent roofing materials, &c.).

FIG. 8.

All these rocks have received the name of "primary," they have no appearance of being stratified or deposited in layers, which appearance seems to be in all cases the result of having at some time been suspended in water and thence deposited gradually as mud, sand, &c., time, pressure, and heat having afterwards altered their consistence. All these consist of the earths described as composing granite, but combined in different proportions. Above these rocks there is a formation of a totally different composition, namely crystalline limestone, commonly known as marble; this consists wholly of carbonate of lime or lime in union with carbonic acid, and its crystalline state appears to have been produced by long-continued heat and pressure. This limestone is by many ranked amongst the primary rocks, although it differs so entirely in its composition which exactly resembles a formation presently to be described (the chalk); however, if this be classed with the primary rocks, then it may be fairly said that all above have resulted from their disintegration and reunion in different forms, by the action of water and vital forces of different kinds. The state of the earth at the close of this the "primary period" may now be considered.

The early history of our globe forms one of the great problems of geology, but there is evidence enough upon which to form conclusions and show that the earth had undergone some great and varied changes embracing immense periods of time, and if the sciences of astronomy, chemistry, mathematics, &c., be brought in to assist the inquiry, some plain facts become evident. Astronomy shows us orbs circulating round the sun (the planets), strictly analogous to our earth, and furnishes us with their densities; these are found to be various, ranging from about six times the density of water to half its density. The planets appear to be at different stages of condensation, and it is not unreasonable to suppose that our earth was once of no greater density than the lightest of them. The inner ring of Saturn is probably in a liquid state, for it is transparent. The substance of which comets are composed is a vapour, so rare and thin that it cannot be compared in density to our atmosphere even, and yet these comets preserve their identity, circulating through immense realms of space with prodigious rapidity. Thus astronomy presents analogies in favour of the supposition that the earth was once gaseous, or at all events of much less density than at present; but mathematical inquiries go much further, and furnish almost proof that the earth was once (if not now) in a liquid state, for the exact form which a liquid ball would assume upon rotating at the rate which the earth does, is exactly that which the globe is found by measurement to possess.

Chemistry has ascertained that the heat of the earth is far greater than any tract of the heavens through which it passes; that this heat could not have been communicated by the sun's rays, for had it been so the surface would be hotter than the interior, the very reverse of which is found to be the fact, and the deeper we go down the higher the temperature is. Chemistry shows further that this heat can be completely accounted for by the condensation and solidification of the earth itself; for the condensation of all gases into liquids, and of liquids into solids, causes a very large portion of latent caloric to become sensible, for example, any quantity of a gas at 60 deg. suddenly reduced to a smaller bulk, would have a temperature higher than 60 deg. A little contrivance has long been in use for obtaining fire by this process, consisting of a cylinder and piston, the rod of which if struck down sets fire to a piece of German-tinder. It is probable that all fire, and every alteration of temperature, are due to this one cause alone.

Now assuming it as a fact that the earth was once in a gaseous state, and that the atoms of this gas or vapour exerted (as they must have done) an attraction towards each other, the result would be that they would press immensely upon those parts towards the centre and cause them to solidify. This act of solidification would produce such an intense heat that the solid would be expanded and fused into a liquid, this continuing until all the more condensible matters had become liquid, the earth would assume its spheroidal form from its rotation, be surrounded by an atmosphere of the least easily condensible substance, nitrogen, together with all the oxygen not wanted to combine with the metallic vapour and form earth. This globe with its atmosphere continuing to roll through the cold regions of space, would gradually lose the heat from its outer part by radiation. A film of cooled and condensed earthy matter would begin to form on the surface by crystallisation, and then would commence all those grand phenomena which it is the province of the geologist to study and explain. This crust consisted of the first-formed granite which (from inequality of contraction in the bulk of the earth) was broken up into fragments and perhaps partly re-dissolved again and again in some places, as it chanced that these contractions were more or less irregular. The result of this crushing and crumbling-up is seen in the coarser parts of the gneiss, called "Grauwacke," which consist of angular fragments of granite more or less imbedded in a cement of the same substance. This could not have been produced by water, as the surface must have been too hot for it to have existed on the earth in any other form than the most highly rarefied steam combined with the atmosphere, and in all probability partly condensed in the upper regions, forming a continuous strata of clouds, or rather water, through which the sun could hardly be seen or its light penetrate, and such a state of things exists at this present time in the planet Jupiter. How beautifully does this coincide with the Mosaic account, "The earth was without form and void, and darkness was upon the face of the earth."

The surface of the earth at this time can be well understood by any one who will take the pains to evaporate any saline solution in a capsule till it is about to crystallise, and observe attentively the pellicle of salt as it forms on the surface; first a partial film will show itself in a few places, floating about and joining with others, then when nearly the whole surface is coated, it will break up in some places and sink into the liquid beneath, another pellicle will form and join with the remains of the first, and as this thickens it will push up ridges and inequalities of the surface from openings and fissures in which little jets of steam and fluid will escape; these little ridges are chains of mountains, the little jets of steam those volcanic eruptions which were at that period so frequent; the surface of the capsule is the surface of the earth, and the five minutes which the observer has contemplated it, a million years.

The next effect of the cooling of the earth would be the gradual condensation of the vapour of water with which it was surrounded; this falling upon the earth formed seas and oceans, leaving only the higher portions exposed above its level. The clearing-up of the dense dark clouds for the first time let in to the earth's surface the glorious and vivifying rays of the sun, and this great effect possibly accords with the earliest record in the Bible of the acts of creation—"And God said, let there be light, and there was light."

FIG. 9—STALAGMITE. FIG. 10.—TEREBRATULA.

The earth being chiefly covered with water, and the air partly freed from watery vapour, then commenced the great creation of organised beings. The air, although to a certain extent, free from vapour, must yet have contained an enormous amount of carbonic acid; this, being less easily condensed than any of the matters which had gone through that process, would still remain there as a gas, and the effect of this superabundance would be to saturate all the water covering the earth with it; this solution of carbonic acid, being capable of dissolving lime, would (as it percolated and rushed in currents through the rocks and inequalities of the surface) become converted into a solution of percarbonate of lime, taking up a large quantity of this earth from the broken-up granite, &c., then this carbonate of lime would be deposited at the bottom of the water in one of two ways—either from pressure, diminution of carbonic acid in the air, and heat of the surface, it crystallised at the bottom in the form of marble (that the water does thus become saturated with carbonic acid and take up lime, is constantly shown by the stalagmites which form on the floors of caverns, where the water thus loaded with percarbonate of lime, evaporating, deposits gradually the carbonate in all sorts of fantastic shapes, as in fig. 9), or the myriads of crinoidians and brachiopodous molluscs (fig. 10) which were about this time created, absorbed it into their systems and at their death deposited their shells, which are made of this earth, at the bottom of the sea; these shells, accumulating through ages into strata, became hardened and partly crystallised by heat, thus forming the limestones, which were the first containing carbonate of lime. That such a collection, from such causes, is quite possible, will be presently shown in describing the chalk formation.

Ages of comparative quiet now appear to have succeeded the first great contraction of the earth's crust, probably millions of years, during which time the tides and currents of the ocean had to wash and wear down all the thousands of projecting rocks or inequalities and dissolve (as before described) all the lime, depositing the sand and clay in those immense strata which form the "transition series;" this appears to have taken place over nearly the whole world at that time, and ages upon ages must have elapsed to form such deposits as the sandstone, claystone, and limestone, in alternation, forming the "Llandilo," "Caradoc," and "Wenlock" strata, more than a mile in thickness; these are by some geologists reckoned among the primary series (by some called the "transition rocks"), and in England form the "Cambrian" and "Silurian" systems.

FIG. 11—TRILOBITE.

In these strata the remains of organised beings are first found, consisting of zoophytes, crustacea (chiefly Trilobites, fig. 11), nautili, crinoidii (stone lilies), and a few ganoid (plate-covered) fishes; these lower forms of animal life in some parts abound in the most prodigious numbers. There must, of course, have been vegetables of some kind previously formed to constitute nourishment for these animals, but scarcely any remains of such exist, except in a few localities.

The Trilobites were amongst the first creatures inhabiting our globe, and it is a curious fact to contemplate, that their eyes (fig. 12) should have been preserved perfect; they present one of those wonderful objects which carry one's thoughts backwards to the early ages of the world, probably many millions of years, and yet it is found by the peculiar structure of the eyes of these Trilobites that they were placed at the bottom of the sea with perfect power to look upwards at the light of the sun through the transparent waters. The same hand and the same power had then Divine care and solicitude for the well-being of His creatures, as great as He has for those of later ages, and these first-formed beings exactly correspond with the account of the creation of animals given in the book of Genesis, "And God said, let the waters bring forth abundantly the moving creature that hath life."

FIG. 12.—EYE OF TRILOBITE.

At the end of the "transition period"—after ages of long-continued disintegration of the rough surface of the earth, and its deposition in strata—after thousands of generations of crustaceans, molluscs, and zoophytes had lived and died, depositing their shells at the bottom of the seas, so as to form strata of the carbonate of lime—a great and terrific convulsion of nature put a stop to all this quiet and systematic order of things; for through these long reaches of time, the physical laws of nature had continued to exert their influence, the bulk of the world had gone on radiating its heat into space, and, as a necessary result, had gradually contracted in size. Now, this radiation had doubtless been much retarded by the badly-conducting surface of solid matter which had everywhere covered it, but, although retarded, it could not be prevented, and although the crust of solid matter may already have been several miles in thickness, yet this in relation to the bulk of the earth would hold but the proportion of the paper on the surface of a twelve-inch globe. As the fluid mass of the earth continued to contract, there would of course be a great stress or crushing-power exerted on the crust, both by its own gravity and that of the air which surrounded it, and about this period it appears to have given way over the greatest portion of the globe, producing enormous rents and fractures, seen in every country in the faults and dislocations of these primitive and transition strata, some of which were driven up by the downward force of others, and left in a perpendicular position, some overlapping each other, &c.; but the greatest effect of this convulsion appears to have been produced by the rocking or rolling surface of the sub-existing fluid world, forming gigantic waves, which, by meeting in opposite directions and thrusting upwards the strata to a great height, formed the mighty mountain-chains of the now-existing earth, which raise their lofty pinnacles above the clouds. Now, these mountains may at first thought appear too ponderous and extensive to be thrown up in this way; but by inspecting the engraved section of a part of the globe (fig. 13), it will be seen how very insignificant a mountain is when compared with the whole world. This section is through Asia from the Persian Gulf to the Yellow Sea, and embraces the highest land on the whole face of the earth, and is drawn on a scale in which the earth is represented by a globe sixteen inches diameter. The rugged and peaked tops of these mountains would be formed by the great fractured masses of the broken strata being thrust upwards and there resting against each other; but who can describe the chasms and hollows which must have resulted when the great wave of melted earth had subsided to its level under one of these huge mountain masses? or the dreadful abyss into which at some future time it and the surrounding country may fall, if they have not already been filled up by the sinking of the surrounding strata. Some of these great waves, when thrust upwards, forced their way right through the point of the mountain and came pouring down in torrents of liquid earth (lava), deluging the surrounding country and filling up the beds of the adjacent seas, casting out cinders and ores of metals—as iron, which appears to have first made its appearance at that time, mingling with the deposits and tinging them of a red colour. These great volcanoes, upon the subsidence of the rock-waves, still (more or less) retained their communication with the interior fiery earth, and are now the greatest safeguards against such a general crushing-up of the strata, for they act as safety-valves against any unequal expansion of the interior (fig. 14). The greatest eruptions of volcanoes or the most terrific earthquakes of modern times, are as the most insignificant trifles compared with what must have taken place to form the inequalities of surface found to exist.

FIG. 13—SECTION OF 40 DEG. OF THE EARTH'S SURFACE, BEING THE SOUTHERN PART OF ASIA, AND INCLUDING THE HIGHEST LAND IN THE WORLD.

The outer uneven line represents the mountains and table-lands from the sea's level, and the lower line shows the depth to which the crust of the earth's surface has been examined—about five miles.

A to B.—Level of sea.
B to second C.—Hindustan.
C to D.—Thibet.
D to E.—Great Desert of Gobi.
F.—500 miles of Earth's radius.
C to C.—The Himalayas, in which occurs the highest mountain in the world, Dhawalagiri, which is 28,174 feet high.

FIG. 14.—BURNING MOUNTAIN.

But the contraction of the interior mass of the earth still continues, and the cavities left by the expulsion of volcanic matters, and the pushing-up of the mountains, may not all have been compensated for by the sinking-in of the strata, so it remains a matter of doubt whether the crust of the earth is sufficiently strong to bear the pressure of its own and the air's gravity, or whether at some future day another contraction will break it up and destroy the whole existing order of things. The shocks of earthquakes are strictly analogous to such catastrophes, but on an immensely inferior scale.

FIG. 15.—LIMESTONE MADE UP OF ENCRINITE.

FIG. 16.—LIMESTONE MADE UP OF CORALS (Favosites polymorpha).

The effects of the last great contraction having subsided the surface of the earth assumed a new arrangement of its matter, and the order of things which caused the deposition of the secondary strata commenced. Sedimentary sandstones were deposited from the washings of the surface by the waters which had not yet absorbed all the superfluous carbonic acid of the air, but continued to do so, and as fast as it became absorbed and saturated with the calcareous matter of the soil, swarms of coral-polypi, which were then formed, began to build their habitations in the warm waters of the ocean and rob them of the carbonate of lime which they contained, leaving them capable of absorbing more from the atmosphere. These little creatures formed immense masses of coral, and together with the "Encrinites" (having stony frameworks, figs. 15 and 16), were the chief artificers of that age, and well did they show what perseverance was able to accomplish, for through the thousands of years of quiet which now succeeded, they must have filled up nearly all the existing oceans with their structures, causing the water gradually to flow from its former beds into other situations, and thus from time to time was changed the position of both sea and land. The strata of mountain limestone which now exist are the remains of what these little polypi then produced, for there is scarcely a portion of this kind of rock, but shows evidences of having been, once, coral, madrapore, or some analogous structure (fig. 17). This mountain limestone sometimes occurs thousands of feet thick, and extends over vast districts both in Europe and America.

FIG. 17.—ENCRINITIC LIMESTONE.

During this period, although there were no great disturbances, capable of displacing the strata, yet there appears to have been frequent small eruptions of volcanic matter through the crevices of the lower strata, filling up all their cracks and vacuities, and in many cases rising to the surface, overflowing with basalt, toadstone, and other volcanic formations; in other cases rising in enormous quantities through openings at the bottom of the seas, partly filling these up, driving off the waters, and thus covering many of the coral formations with coatings of sand to a great thickness, raising up others into considerable elevations, and forming hills and fresh tracts of earth.

FIG. 18.—FOSSIL TREE FERNS.

During this long period of comparative quiet most of the irregularities on the surface of the earth became worn down, and extensive swamps were produced by partial evaporation of the inland lakes. These swamps were subject to occasional inroads of the sea, and at times formed shallow lakes or lagoons; in these grew the most luxuriant vegetation, gigantic pines, tree-ferns (fig. 18), equisetacæ, &c. These plants, nurtured by a hot and moist climate, acquired a great luxuriance of growth, and must have formed forests of such great density, that there is nothing existing at the present time worthy to be compared with them, even in the hottest climates. Such fertility appears to have been dependent upon the conditions of the air and earth, the former containing more carbonic acid (the food of vegetables) and the latter a greater amount of warmth, than at present; these two circumstances, so favourable to the growth of plants, were equally unfavourable to the existence of air-breathing animals, to whom the carbonic acid would be fatal poison.

Thus, in the mighty hands of God, the air was undergoing a gradual purification, to fit it for the animals He intended to create; the polypi were extracting from the water all the carbonate of lime it was absorbing from the air and earth, and fixing it in the soil, to be of use in a hundred ways at some future time, while the vegetation growing in abundance extracted it from the air, and fixed its carbon in their leaves and substance generally; these vegetables, decaying and falling upon the surface of the earth, accumulated there for ages, and formed a carbonaceous matter which was afterwards changed by time and pressure into coal. The same thing (on a very much smaller scale) is taking place in the tropical forests of the present age; there the surface-soil is quite black, and consists of nothing but decayed leaves and wood for several feet in depth, but in the present time there are hosts of insects, every one of which feeds upon this vegetable matter, preventing to a great extent its accumulation, while in the former age there was nothing to destroy it when once deposited on the ground; so that the carbon of these forests of the secondary period, existing through perhaps tens of thousands of years, extracted from the air a sufficient quantity of vegetable carbonaceous matter to produce thick seams of coal, even when compressed by the superincumbent strata. These forests were subject from time to time to inroads of the sea produced by the before-mentioned causes, and thus it is found that the seams of coal are often buried by several hundred feet of sand, clay, shale, &c., above which the same growth recommenced to form a second strata of coal, and ages must have elapsed whilst each of the numerous seams which interstratify the "coal measures" were forming. This coal, preserved in the depths of the earth, now forms the greatest treasure of the mine, and ironstone (from which iron is procured) would be almost useless but for the occurrence of these two minerals together with limestone (used as a flux) in the same locality, and it is this fortunate circumstance which enables England to produce such vast quantities of iron at such a cheap rate. The quantity of coal consumed in the iron-smelting works and for fuel generally, is beyond what could have been imagined a generation or two back, being somewhere about 50,000,000 tons annually, the coal brought to London alone in 1856 being 1,271,800 tons, yet there is such a plentiful supply of this valuable fuel in Great Britain alone that, supposing the annual consumption to rise to 70,000,000, it would serve (according to computation) a thousand years. Who shall say from whence fuel will then be obtained? probably from some other source provided by the foreknowledge of God, as was shown in the formation of the coal itself; for who could have imagined, a thousand years ago, when England possessed such immense forests, and wood was the universal fuel, that this very wood would become too scarce and valuable to be used, and that a substitute would be dug out of the earth!

The coal-shales (thin layers of claystone found in the coal seams) furnish beautiful specimens of ferns and other plants turned into coal (fig. 19), or leaving their perfect impressions in the clay. The coal formation occurred during the latter part of one of those long eras of tranquillity which supervened upon the contraction and breaking-up of the older strata; but the laws of nature are immutable, and these days of comparative quiet again came to a close. The same phenomena before described again occurred, and there is hardly a square mile of these strata but shows evidences of the terrible convulsion which desolated the earth. Some of the strata were raised, others depressed, and some lost altogether, the cracks and flaws being filled with liquid lava or basalt, which in many cases rose upwards through them and overflowed the surface. Many of the cracks of this, the "carboniferous system," are filled with sulphuret of lead called "galena," the ore from which all the lead of commerce is obtained; it is not well known how the veins of this and similar substances got into these crevices, but it is probable they were injected in a fluid state by some unequal pressure on the liquid beneath, or deposited by electrical action.

FIG. 19.—FERN (Pecopteris ligata) FROM UPPER SHALE, SCARBOROUGH.

The great world of vegetation was thus destroyed, giving place to new forms of animal and vegetable life. The temperature, all this while sinking, had reached a degree somewhat resembling the hottest regions of the earth at the present day. The waters had changed their localities, new mountains and new continents had made their appearance, and again did the ever-active waters begin to demolish and wear down the asperities of the surface and deposit the results upon the strata below in the form of the new red sandstone and magnesian limestone, the former containing iron in great abundance, and the latter magnesia (an earth not met with before), both of which substances were probably ejected as volcanic products and afterwards combined with the carbonic acid of the air.

FIG. 20.—LABYRINTHODON.

FIG. 21.—IMPRESSIONS OF FEET IN NEW RED SANDSTONE.

During the formation of these strata there appears to have been both birds and quadrupeds of many kinds, together with a reptile much resembling a frog, but of great size, being five or six feet long, called the "Labyrinthodon" (fig. 20). The oxide of iron, or some other agent appears to have prevented the fossilisation of the inhabitants of these strata, for but few of their organic remains have been preserved; but very curious evidences of their existence nevertheless remain, in the impressions of their feet upon the ground they trod (fig. 21), which appears to have been a moist clay or mud peculiarly adapted to receive impressions, and which having been in many places covered over with a stratum of fine sand, and then abandoned by the sea, the whole have hardened into stone, and being now separated, the one contains their footprints and the other perfect casts of them! Nor are these foot-marks all that these sandstones have to tell us of their day; for the ripples of the waves, and even the little pits made by drops of rain as they fell, are in this most marvellous manner preserved, forming objects of wonder and admiration for us mortals to contemplate, and themes whereon the devout mind may pour out its tribute of praise to their Great Author. How evident it is that the Creator designed beforehand that we should search for these hidden evidences of His handiwork, or for what purpose were they thus stored up and preserved? "Seek, and ye shall find, knock, and it shall be opened unto you," are the words of God, and they apply as fully to the material wonders of His works as to the mysteries of His revealed Word.

As the strata below the new sandstone formation was called the "Carboniferous" system, from its containing much carbon in the form both of coal and carbonic acid, so this has been called the "Saliferous" system, from the occurrence in many places of strata of "rock-salt" or crystallised chloride of sodium, and (where the rain finds its way down and dissolves it) of brine springs; these (in England) exist chiefly in Cheshire and Warwickshire, but in Poland and Hungary they exist on a much larger scale, the rock-salt being nearly a thousand feet thick. It has been said that these strata of salt were formed by the evaporation of salt lakes, but it is much more probable that salt is one of the natural materials of the earth, and that both salt lakes and oceans have become salt from dissolving out these strata wherever they have come into contact. The next sediment deposited over the new red sandstone is called the "Lias," a sort of limestone mixed with clay of a blueish-grey colour, and upon this lias is again deposited the various strata known as the "Oolite" (Roe-stone) system, from its appearance resembling the roe of a fish, it consists of small rounded particles of limestone set in a cement of the same substance worn down fine.

FIG. 22.—AMMONITE (Henlyi). FIG. 23.—PENTACRINITE.

These strata furnish a great many organic remains, especially the shells of the conchiferous mollusca and cephalopods, as Ammonites (fig. 22), Belemnites, Nautili, and Pentacrinites (fig. 23), of which a great many varieties are found, also the remains of gigantic reptiles, as the Ichthyosaurus (fig. 24), Plesiosaurus (fig. 25), and others. New forms of animal existence seem to have been created in this period in great abundance, and the waters of the earth once again became the theatre of deposition for the shells and polypidomes of zoophytes and molluscs, which swarmed them in myriads, and another great group of rocks began to be formed, namely, the chalk or "Cretaceous" system, which form the cliffs and downs of our south coasts, and strata of great extent in nearly every part of the world; it differs from limestone only in not being so hard, which is supposed to arise from its not having undergone the changes caused by heat and pressure.

FIG. 24.—ICHTHYOSAURUS.

FIG. 25.—PLESIOSAURUS.

FIG. 26.—NAUTILUS INEQUALIS.

FIG. 27.—ORGANISMS FROM CHALK.

The chalk is interstratifìed with lines of sand, and the lower part is almost entirely sandy, forming the gault and greensand deposits; these each contain organic remains, and must have been the original sand of the sea-bottom before the chalk was deposited on it. These seas must have been the residence of a vast number of reptiles, for the gault contains an enormous number of nodules of what appears to be stone, but which upon closer examination, prove to be coprolites, or portions of the excrement of those creatures partly fossilised, but still retaining phosphate of lime enough to render them valuable manure, and these—like the coal—after being buried in the earth for thousands of years, are now being brought into use. In these coprolites may be constantly seen the teeth and bones of fishes, together with portions of echini and crustaceans, which had passed through the intestines of these saurian reptiles. Fig. 26 is the shell of a small nautilus (Nautilus inequalis) thus found.

FIG. 28.—AMMONITE FROM THE CHALK.

This chalk is of a white colour, very light and porous; under the higher powers of the microscope, it appears to be made up of organic forms, as "Foraminifera," and portions of various kinds of shells, crushed and broken into minute fragments (fig. 27). Dr. Carpenter, in his work on the microscope, says: "Many parts of it (the chalk) consist in a great measure of the minuter parts of the smaller kinds of Foraminifera, whose shells are imbedded in a mass of apparently amorphous particles, many of which nevertheless present indications of being the worn fragments of similar shells, or of larger calcareous organisms. In the chalk of some localities, Foraminifera constitute the principal part of the minute organisms which can be recognised with the microscope; in other instances the disintegrated prisms of Pinnæ, or other large shells of the like structure (as Inoceramus), constitute the great bulk." The fossil remains in the chalk are very numerous and are all of a marine character, the ammonites (fig. 28), belemnites, and other cephalopods, were very prevalent, as were the various Echinodermata, as the Hemicidarus intermedia (fig. 29), together with numerous univalve and bivalve mollusca, various crustacea, fish and reptiles. There was some considerable wonderment a few years ago expressed at the skeletons of men being found in the chalk at Guadaloupe; but it has been ascertained that this chalk is a modern formation, being produced by the sea washing and disintegrating the adjacent coral reefs, and depositing a fine white sediment of broken coral on the shore which can hardly be distinguished from ancient chalk; the same process is taking place at the Bermudas and other islands of the West Indies.

FIG. 29.—ECHINUS (Hemicidarus intermedia, Chalk).

In many places the chalk strata contain single lines of flints, running for miles parallel to the layers of chalk; these flints consist of almost pure silica, and it has been a matter of wonder how they got there, but on considering how slowly the deposition of chalk must have taken place, from the formation and death of millions of minute creatures, and that it was once the bottom of a deep sea, the disposition of the flints in lines would be accounted for, supposing them to have been formed on that sea-bottom, and the source from which they have been derived is doubtless the petrifaction of sponges, madrapores, &c., there formed. Dr. Carpenter (in the work before referred to) says: "It may be stated, as a fact beyond all question, that nodular flint and other analogous concretions (such as agates) may generally be considered as fossilised sponges or alcyonian zoophytes, since not only are their external forms and their superficial markings often highly characteristic of those organisms, but when sections of them are made sufficiently thin to be transparent, a spongy texture may be most distinctly recognised in their interior."

FIG. 30.—TERTIARY FORMATION.

During the deposition of these secondary strata in the hollows of the surface, but little alteration of the relative situations of sea and land could have taken place, as the deposits for the most part lie conformably to the same hollows or "basins" (fig. 30 will illustrate this); but after the deposition of these strata, there appears to have been a very great disturbance, many chains of mountains were cast up (as the Apennines), carrying upwards with them these deposits; some of the strata were so displaced that they were left in a perpendicular position, as may be seen in several places at the south side of the Isle of Wight. These disturbances, however, did not amount to so general a convulsion as those before described, nor is it known whether all the effects produced on these strata took place at or near the same period of time; they nevertheless appear to have produced an almost total change in the situation of the land and sea, for the "downs" of chalk (on the southern coast of England, for example) were, before these changes, the beds of seas. This is the last of the great convulsions which the earth has undergone, for the tertiary strata which afterwards began to be deposited rest in the hollows or basins (chiefly in the chalk) then left; the alterations in and since these deposits appear to consist chiefly of the upheaval of certain localities, the depression of others, the evaporation of inland lakes, and the wear and tear of the land from these causes, which are still in continuous action (as from the washing down of cliffs by the sea, and the formation of mud deposits at the mouths of rivers), or the volcanic agencies which in some places (as in Ireland) have cast up basalt over the chalk.

The tertiary strata contain remains of most of the classes of animals now in existence, but yet differing greatly in species, and as the strata approach the surface those species become more and more general; the plants also approach more nearly to those of the present time, but still most parts of Europe possessed a climate almost tropical. The tertiary strata consist chiefly of marine and fresh water deposits in the form of sands and clays, as the "London clay," which extends under London, resting upon a basin of chalk. The last deposits, forming the superficial layer of earth, and the formation last deposited before the creation of man, are called the Diluvium and Alluvium, and contain numerous remains of mammalia, birds, reptiles, and fishes. One of the most extraordinary animals of this period was the Dinotherium, a sort of walrus, which is supposed to have been the largest of quadrupeds, if indeed it was one (fig. 31). The quadrupeds of this, the "Pliocene" formation, are thus described by Professor Owen in his "History of British Fossil Mammals."

FIG. 31.—SKULL OF THE DINOTHERIUM.

FIG. 32.—MAMMOTH, TELEOSAURUS, AND GLYPTODON.

"At the period indicated by these superficial stratified and unstratified deposits the Mastodon had probably disappeared from England, but gigantic elephants (fig. 32), nearly twice the bulk of the largest individuals that now exist in Ceylon and Africa, roamed here in herds, if one may judge from the abundance of their remains. Two horned rhinoceros, of at least two species, forced their way through the ancient forests or wallowed in the swamps. The lakes and rivers were tenanted by hippopotami, as bulky and with as formidable tusks as those of Africa. Three kinds of wild oxen, two of which were of colossal size and strength, and one of them maned and villous like the bonassus, found subsistence on the plains. Deer as gigantic, in proportion to existing species, were the contemporaries of the old Uri and Bisontes, and may have disputed with them the pasturage of that ancient land. One of these extinct deer is well known as the Irish elk, by the enormous expanse of its broad-palmed antlers (fig. 33). Another herd proves more like those of the wapiti, but surpassed that great Canadian deer in bulk. A third extinct species more resembled the Indian Hippelaphus, and with these were associated the red-deer, the rein-deer, the roebuck, and the goat. A wild horse, a wild ass or quagga, and the wild boar, entered also into the series of British pliocene hoofed animals. The carnivora, organised to enjoy a life of rapine at the expense of the vegetable feeders, to restrain their undue increase and abridge the pangs of the maimed and sickly, were duly adjusted in size and ferocity to the fell task assigned them in the organic economy of the pre-adamite world. Besides a British tiger, of larger size and with proportionately longer paws than that of Bengal, there existed a stronger feline animal (Machairodus) of equal size, which from the great length and sharpness of its sabre-shaped canines, was probably the most ferocious and destructive of its peculiarly carnivorous family. Of the smaller felines, we recognise the remains of a leopard, a large lynx, and of a wild cat. Troops of hyenas, larger than the Crocuta of South Africa, which they most resembled, craunched the bones of the carcases relinquished by the nobler beasts of prey, and doubtless often themselves waged the war of destruction on the feebler quadrupeds.

FIG. 33.—IRISH ELK.

THE PALEOTHERIUM.

"A savage bear, surpassing the Ursus ferox of the Rocky Mountains, found its hiding-place, like the hyæna, in many of the existing limestone caverns of England. With the Ursus spœlus was associated another bear, more like the common European species, but larger than the present individuals of the Ursus Arctas. Wolves and foxes, the badger, the otter, the foumart, and the stoat, complete the category of known pliocene carnivora of Britain."

In the time of these the last of the tertiary strata, there appear evidences of a degree of cold much greater than at present exists; this seems to be pretty well proved by the "boulder formation," or prevalence of erratic blocks of stone, the progress of which have been traced from their sources of origin to hundreds of miles distant, and there is no conceivable power which could have carried them but the floating fields of ice or glaciers; both of these sources are capable of this removal, for it is not uncommon to find large pieces of rock and layers of gravel floating on masses of ice. Glaciers are formed by the snow on the sides of mountains becoming hardened by being partially melted and again frozen, and at every melting the fluid tends to descend, when it again becomes frozen, always adding to the lower part and carrying away from the upper. In this way whole glaciers of many miles extent become unfixed, and as fresh snows are added to their upper parts, they descend slowly, entangling with them and tearing away the rocks in their vicinity. When they arrive at the sea and float forth, these rocks are borne with them.

But there are as yet no traces of man, not one small fragment of his skeleton, not one minute relic of his constructive powers, although the bones of man are as capable of preservation as those of any other animal, being the same in structure and composition; the remains of hundreds of fragile insects, seeds, leaves, and all sorts of organic structures, are found perfectly preserved (fig. 34). The only way, therefore, of accounting for the absence of any organic remains of man, is the assumption that he was not then created; and this is confirmed by the fact that in the very uppermost layers of the earth's surface his bones and the works of his hands are found in great abundance; it is therefore with good reason that we come to the conclusion, that he was the last creature formed by his Maker. That the creation of man was pre-intended by God, seems also almost proved by the numerous objects before created, capable of ministering to his use and happiness—capable of exercising his constructive and inquiring capabilities—suitable to his imagination and tastes, and his only, and which would serve no purpose of utility to the mere brutes. Of what use, to any creature but man, is coal—of what use the metals? Of what avail is it to any of the lower animals, that God has caused glass and other transparent substances to have the power of refracting the rays of light? but without which not one-half of our knowledge of His wondrous works would ever have been obtained, for it is upon this property alone that the powers of the telescope and microscope depend. Of what use to any but man are fire, artificial light, and galvanism? and yet all these were created long before man was.

FIG. 34.—FOSSIL LEAVES.

FIG. 35.—SCULPTURE FROM NINEVEH.

It has often been asked, What does man gain by the study of the sciences? Besides the enlarged views which they give him of his Creator's goodness and power, they at this time are fast reaching towards the demonstration of many obscure passages of His Holy Word as revealed to us in the Scriptures. The study of truth can moreover never lead one into error, and a habit of drawing correct conclusions from the facts presented is useful to every one. Geology has confirmed one great truth in Scripture, and overthrown the greatest groundwork of Deism, for it had been asserted by many that man (and indeed all other creatures) had risen to his present state by slow developments, and no proof to the contrary had ever been given. But geology has shown that at a certain era man was created, that (as is stated in Scripture) he was the last of God's works, and that neither before that time had he existed in an undeveloped form, nor since has he altered one jot from his original configuration; and the same may be said of all other creatures, whatever may be pretended to the contrary, for from the sculptures brought from the ruins of Nineveh (at least 3000 years old), there appears the same external form (fig. 35), both of man and what animals are there depicted, and his and their habits were described by the very earliest writers to be then as now. But with respect to the form of the earth's surface it is otherwise, there being a slow but continuous change. Those parts of the land exposed to the tides and action of the waves, are washed away, and the rivers are constantly bringing down soil to deposit it at their mouths, forming those tracts of land known as "deltas;" every wind that blows takes away some dust from the higher and deposits it on the lower parts of the earth's surface, so that, to use the words of the Prophet Isaiah, "every valley shall be exalted and every mountain and hill shall be made low." But this alteration is so slow that it takes hundreds of years to make but a small difference, yet a difference there undoubtedly is, and a time must come when the alteration will be such as has been shown to have taken place in far-back times and recorded in the strata in evident language, for though the changes are slow the result is inevitable. It has been ascertained that the northern part of Sweden has been steadily rising and the southern part sinking to a corresponding degree for many centuries past, and that the west coast of Italy has been elevated for ages past, at the rate of not quite an inch yearly. Volcanic actions are raising some lands and depressing others (in the earthquakes of 1822 and 1835, the whole of Chili from the Andes to the sea, and probably the bed of the sea to an unknown extent, was elevated considerably), rain and the rivers carry away land into the sea, the beds of many seas are being filled up by coral polypes and protophytes, so that the beds of these seas must ultimately be the land whilst the lower parts of the land will become sea.

After these various changes upon the surface of the earth, from a climate hot beyond anything now existing, from a surface rocky and full of fissures and inequalities, studded with islands and continents, abounding in marshes and swamps—from a state of atmosphere in which the higher animals could not live—to the present division and separation of land and water, of oceans and seas, of islands and continents, well supplied with rivers to drain off the superfluous fluid and supply highways easy to traverse in boat or canoe, the world remains, a fitting habitation for the creatures God has placed upon it on every hand. Forests to shelter the wild animals from the rains and heat of the sun; waters for those who dwell or delight in them; metals, stone, earth, and wood for man to exercise his ingenuity upon, and other innumerable things contributing to his comfort or luxury—all freely given by the hand of his Heavenly Father for his well-being and delight, that he may lack no excuse to worship and adore Him, and this delightful earth, as Milton says:—

Brought forth the tender grass, whose verdure clad

Her universal face with pleasant green,

Then herbs of every leaf, that sudden flower'd

Opening their various colours, and made gay

Her bosom smelling sweet: and these scarce blown,

Forth flourish'd thick the clustering vine, forth crept

The swelling gourd, up stood the corny reed

Embattled in her field, and the humble shrub,

And bush with frizzled hair implicit: last

Rose as in dance the stately trees, and spread

Their branches hung with copious fruit, or gemmed

Their blossoms; with high woods the hills were crowned.

With tufts the valleys, and each fountain side,

With borders, long the rivers: that earth now

Seem'd like to heaven, a seat where gods might dwell

Or wander with delight, and love to haunt

Her sacred shades.

After all these various elevations and depressions, the land remains at this present time in the form of large tracts occupying about a third of the superficial area of our globe. The largest tract is made up of Europe, Asia, and Africa, which constitute one continuous area, Africa being almost severed from the others, but still united by the Isthmus of Suez; the tract next in size to this is made up of North and South America, these again are nearly severed, but still united by the Isthmus of Panama or Darien; next come Australia and Greenland, but these, although very large, are yet not to be compared in size with the former two; there are numerous other large islands, as Borneo, New Guinea, New Zealand, Madagascar, Iceland, England, Ireland, &c., and scores of smaller ones.

The temperature of the earth (as a general rule) is greatest on the equator and diminishes gradually towards each pole, but this is by no means invariable, for two places of the same latitude may be very different in climate, and a system of lines passing round the earth from east to west, would each pass through regions of various temperatures, or what is the same thing, lines made to follow the same temperature would have to make various curves and contortions; such lines have been constructed and are called "isothermal" lines. The causes of this are to be found in the various currents of the ocean, the tides and winds, and in the proximity to the ocean of snow-clad mountains and arid plains. The variation of latitude in these lines sometimes reaches as much as seven degrees.

Europe contains about 3,900,000 square miles of surface, and is separated from Asia by the Caucasus, Caspian Sea, River Ural, and Uralian Mountains. It is about 3000 miles long and 2400 broad, about two-thirds being plain and table-land and one-third mountain land. The chief mountain ranges are those which run through Norway and Sweden in a north-westerly direction, and the mountain system along the south part from Portugal to Turkey. This last includes the Pyrenees, which runs from the Bay of Biscay to the Mediterranean, the highest peak of which is Mont Maladeta (11,500 feet); the Alps, the highest point of which is Mont Blanc (15,748 feet); the Apennines, the highest point of which is Mont Viso (12,586 feet); the Carpathian Mountains, extending from Presburg in Hungary towards the sources of the Waag and March, the highest point being Mont Lemnitz (7962 feet); and the Balkan range, which may be considered a continuation of the Alps eastward, runs as far as the Black Sea, together with many inferior ranges and branches.

The climate of Europe embraces a range from the temperate to extreme cold. It is bounded by the Arctic Ocean on the north, Asia eastward, the Mediterranean Sea southward, and the Atlantic Ocean to the westward; it contains two great inland seas, the Black Sea and the Caspian Sea. There are three great volcanoes in Europe, Hecla, Vesuvius, and Etna, but the plains of Auvergne contain many which are extinct.

Asia contains the highest mountains and the most extensive table-lands in the world. It is somewhat square, being bounded northwards by the Arctic Ocean, westward by Europe, southward by the Indian Ocean, and eastward by the North Pacific, and contains about 17,500,000 square miles; the greater part is made up of two extensive tracts of elevated land called table-lands, although these are often varied by valleys and mountain chains of great extent, yet as a whole, they are from 5000 to 10,000 feet above the level of the sea. The eastern table-land is that of Thibet and the Great Desert Gobi, and the western that of Persia.

Asia contains many great mountain chains, the chief of which are the Himalaya Mountains, which run along the centre of its southern part and contain some of the highest peaks in the world; the Dhawalagiri is 28,072 feet high, but there are some others supposed to be as high.

The Altai or Gold Mountains, forming a boundary to the lowlands of Siberia, the highest peak of which is called the Katunia Pillars, and is 11,000 feet high.

The Thain-schan or Celestial Mountains, the Kuen Lun, and the Hindoo Coosh, all of which run pretty nearly east and west, while the ranges called Uralian, Bolor, Khingan, and Chinese chains run nearly north and south.

Africa is somewhat triangular, with its base towards Asia and its apex pointing southward. It is bounded northwards by the Mediterranean Sea, and at its east side by the Red Sea and Indian Ocean, while the Atlantic flows on its south-west side. In Africa is the largest desert in the world, the Great Desert of Sahara; it occupies nearly all the northern part, the southern has but few mountains of great extent, but from their elevation and the amount of waters brought down by rivers, it is supposed that the centre has very high table lands. At the north-western part is an extensive mountain system (the Atlas) covering with its branches nearly 500,000 square miles, and sending its slopes to bound the great Desert northwards.

The great tract of land comprising North and South America extends in a longitudinal direction pretty nearly north and south through 130 degrees of latitude, or nearly 8000 miles. This great tract is divided by a narrow neck of land (the Isthmus of Panama) into two pretty equal portions; the northern part is peculiar, from containing a number of lakes of immense extent, deserving well the name of inland seas, and both northern and southern divisions for the great number and extent of their water-courses. The whole of this great tract of land is traversed from end to end by an extensive chain of mountains, the longest in the world; at its southern part it forms the Andes, from which a range is continued through the Isthmus, and onwards to form the Rocky Mountains. In the southern division this immense chain passes on the west side of the land close to the sea, is of great elevation in some parts, has some of the highest mountain peaks in the world, and volcanoes also, the highest being in the Andes (Popocatapetl is about 16,000 feet high); but from the western side of the continent the land descends gradually to the eastern. In South America are some of the highest table-lands known, great elevated tracts in connection with the mountain ranges.

Australia in its interior is but little known, but the whole aspect of the island appears to be flat, and to have but little elevation, while Greenland and the great tracts of the northern regions beyond, deserve more the name of glaciers, being almost entirely a mass of barren rocks and snow.

The water-courses of these various great tracts of land are all determined by the formation of the surface, but the amount of water which is carried into the oceans by the rivers of any district is always in proportion to the amount of vegetation in that district; thus in Europe, Asia, and America, the number and extent of these correspond with the great fertility of the soil, while the northern and western part of Africa—the Great Desert—give off scarcely any of adequate extent, the Nile appearing to receive its supply from the central parts further south. The reason of it is this: wherever there is vegetation, either in the form of grassy prairies or forests, there is also a great reduction of temperature from the radiation and evaporation, and the consequent formation of rain, dew, or snow, which falling on the ground produces streams, &c.

Excepting the great tracts of land named, and islands too numerous to be mentioned, the whole surface of the earth is covered with water, the great divisions of which (called Oceans) are, the Arctic Ocean, to the north of Europe, the Atlantic, between America, Europe, and Africa, the Pacific between Asia and America, and the Indian Ocean between Africa and Australia.

The foregoing is a very bare outline of the land and water covering the surface; it may suffice, however, to call to mind the main features of the earth as it is now disposed. There can be little doubt that the great variety of climate, whether hot or cold, moist or dry, is one of the greatest sources of happiness that can be well imagined; it stimulates to research, travel, and inquiry into the works of God; every change experienced tends to make man search for further change, every new scene makes him compare it with others; and the acquirement of a knowledge of places, and a general idea of the whole world, expands his mind, enables him to appreciate the good gifts he has received, and affords a source of satisfaction beyond almost any other kind of enjoyment.

[THE WATERS.]

SEA-COAST.

How grand is the ever-moving ocean! how majestic its voice, how terrible its anger! how beautiful every colour that is reflected from its dancing spray, and how balmy the air which is wafted from its bosom to refresh the heated earth, which, under the glare of a summer's sun, seems parched with thirst. How refreshing to the senses is the change from the dry heated grass on a midsummer day—from the dusty roads—from the smoke begrimed town, smelling of dirt, and heated by the reflection of the sun's rays from bricks and stones till it becomes a furnace—from the close dark habitations of the city—from the rattle, excitement, and continual noise of vehicles and human voices—from the corroding cares and depressing influences attending the fierce "battle of life"—to the cool and gentle breeze, "the wide o'er-arching canopy of heaven," the murmur and ripple of the sea, to the clear and exhilarating air, free from soot and laden with the odour of the ocean.—Oh what a desirable change! all human nature seems to own it, and hasten to the shores of the great watery world, that they may contemplate one of the greatest and grandest of God's works with admiration and thankfulness, and be re-animated by its health-giving powers.

It is a wonderful sight, and one which fills our minds with reflection; here we see many of the laws of nature exemplified on a great scale. The laws of gravity keep the surface of the ocean perfectly spherical as a whole, while those of equilibrium keep it in constant and ever-varying motion, the laws of attraction produce the tides, and those of reflection and refraction cause its surface to assume all sorts of colours and tints.

"Great art thou, Ocean, and unknown

The creatures springing into life from thee,

Earth's farthest shores full proudly thou dost own,

The cradle of thy wave from iced to torrid zone."

The ocean is full of life, both vegetative and animal; myriads of both classes have their natural habitation in the sea, and the shore is often, after a gale, strewed with curiosities well worth the contemplation of those who devote their minds to thought. How many varieties of sea-weed have you gathered? perhaps twenty; not three of them are sea-weed at all! they are living animals, either zoophytes or molluscs, every branch of that "flustra" contains a thousand living beings, every spray of "sertularia" as many more, that other piece is the "bugula neretina" and also owns a colony of animals: the next is indeed a member of the vegetable kingdom, its beautiful crimson colour makes it a conspicuous object, and there are many specimens of the same plant, but of all shades of red, crimson, and purple, it is the "plocamium coccineum." And thus it is with every object we view, a knowledge of it brings us to respect and admire it more and more as that knowledge increases, and none more so than some of the productions of the sea. It is here we find specimens of the star-fish, the sea-urchin, and other radiata. Shells of all kinds—both living and dead—belonging to the various tribes of mollusca; crabs, shrimps, and other crustaceans, besides the endless varieties of pebbles and other specimens of worn-down rock, the effects of constant attrition.

If we turn from the shore and gaze upon the horizon, what a marvellous object it is—ever receding as we recede, ever rising as we rise, and never nearer nor farther away. This rising of the horizon, so as to be always opposite to our eyes, is because the higher we are up the more we see. On looking at the horizon we do not look on a perfect level, (if we did, being above it, of course we could not see it at all) but the depression of the line of vision is so slight as to be quite unable to be appreciated; yet, small as it is, it enables us to see a considerable space of the ocean, and the higher we rise—at the same angle—the more we see. The edge of the horizon also appears curved, being higher in front of us than on either side. This is only so in appearance, for if any one were to place a piece of string (stretched tightly between the hands) before his eyes, and bring it up till it is on a level with the horizon, he would soon see that the string and the horizon were both perfectly straight and exactly corresponding with each other.

From the horizon we turn round and look at the chalk cliffs, those white walls from which our native isle has received the name of "Albion." How were they produced? by the constant lashing of the restless waters, which are constantly wearing them away; but they are beautiful objects, full of marvels and records of bygone ages, when their tops were at the bottom of the deep seas.

The sea is a general name given to all the greater collections of water throughout the world, although, in a restricted sense, it is applied to those tracts of water of a secondary size, as the Black Sea, the Baltic, and the Mediterranean, the term "ocean" being applied to the larger tracts of water, as the Atlantic Ocean, the Pacific Ocean, &c. All the great oceans and seas unite, and, in reality, form one great world of waters, spread out and covering all the lower parts of the earth, the term "lake" being applied to collections of water surrounded by land, although the Caspian Sea retains the name of sea, and some of the great lakes of America may well deserve such a name.

The waters of the sea fill up all the lower parts of the earth, so that, almost without exception, the land is higher than the water, and as the land in some places rises but a few feet, and in others as many thousands, so, beneath the sea, the land sinks in many places but a few feet, and in others perhaps as many thousands as it is known to rise above it. The sea always maintains the same general level, although in past ages the land has risen and fallen, sometimes in one place and sometimes in another; indeed, the same process is taking place every day, but in so slow a manner that centuries are required to make any great alteration; while some tracts of land are being encroached on by the action of the waves, others are being added to and elevated by accumulations of mud and sand, or raised by the action of earthquakes and volcanoes, which throw up under the sea, as well as on the land, vast quantities of melted earth or lava, forming strata known to geologists as basalt, tufa, &c., or eject showers of ashes and dust in such prodigious quantities as to cover many hundred square miles of the earth's surface. It was by one of these showers of ashes from Vesuvius that the cities of Herculaneum and Pompeii were buried. So that, as a whole, although the sea is continually altering slowly its position, yet it pretty equally maintains the same elevation. At first thought it may be supposed that the rivers constantly flowing into the sea would alter its level, for some are so large that millions of tons of water are brought by them into the sea every hour, and there are thousands of rivers and rills which, night and day, pour in their tribute of waters; but God has wisely and kindly arranged these things (like all others) so that they shall afford us innumerable comforts, and yet not raise up the sea so that it shall cover the land, for it requires but a moment's consideration to be convinced that all this water which flows into the sea must first have been abstracted from it, and it is in this way—when the winds blow over the sea, they absorb or take up a certain quantity of the vapour which continually rises from it; for air absorbs a certain quantity, and a certain quantity only, of the vapour of water; but this quantity is determined by certain circumstances, for instance, the warmer the air, the more it will absorb, the less the pressure on the air, the more it will absorb, and the drier the air, the more it will absorb, that is, the less moisture it has already got, the more will be required to make up that quantity which the other circumstances permit it to contain. Now, what takes place if a warm, dry, light current of wind blows over the sea, landward? Why, all the vapour given off by the sea, to the amount of millions of gallons, is absorbed and carried inland by the wind or current of the air, and this continues onward, laden with moisture, until it meets with one of the several circumstances which shall cause it to be incapable of holding the quantity of moisture which it has already got; for instance, it meets with another current of air colder than itself, these mingle, the vapour of water is condensed by the cold, and a cloud is formed. This consists of minute particles of water suspended in—not absorbed by—air; these particles gradually collect, and down falls the rain on to the earth. This drains off from the surface, forming rills, which collect as they descend, by their own weight, into the lowest channels of the ground, and form into streams and rivers, and back into the sea comes the water which the air had taken away, with this difference, that it is free from salt and fit for the many uses to which fresh water alone can be applied; when the vapour rises from the sea, none of the saline matters rise with it, for, although the water is volatile, yet they are not, and this is the whole source of fresh water. It is distilled in the great laboratory of Nature, and gives nourishment to all the living beings who dwell on the land and in the rivers and lakes; or the rain may sink into the earth and be carried for miles and miles under ground, running through some porous stratum, such as gravel, until it flows out in the form of a spring, bubbling up amongst flowers and weeds, and forming the source of some river, which receiving the rain and all the springs in the country through which it flows, finds its way back into the ocean at last.

MOUNTAIN STREAM.

This is the way in which all rivers and streams are formed. An enormous extent of land thus drained gives rise to thousands of rills, which collect into streams of goodly size, meandering through valleys and pouring their tribute of waters into a main stream, which at last accumulates by additions to its course, and becomes one of those great water-courses which form the highway through a continent. The Amazon, Hoang-Ho, Ganges, Nile, Danube, and Volga, may be cited as some of the greatest water-courses and highways of civilisation. These great rivers are navigable for large ships, even for many hundreds of miles, and it is most fortunate that this navigation is so seldom impeded by falls; for these, although among the grandest and most beautiful objects of nature, yet put a stop to the navigation of a river which would otherwise be passable for hundreds of miles further. Rivers which run through districts subject to periodical rains, or those whose sources lead from mountain slopes where vast quantities of snow are deposited in winter which melts on the approach of summer, are at such seasons of the year suddenly augmented, and generally overflow the banks and inundate the country for miles. This is in many cases a very great misfortune, as it spoils the land, reducing it to a swamp, but not in every case; the overflowing of the Nile brings down with it a great quantity of fertilising vegetable matter, and serves to manure the whole district, for the soil being extremely porous and the heat great, the moisture is soon got rid of, and hence it was a custom of the Egyptians to celebrate the rising of the Nile by feasts and ceremonies.

Lakes are formed in the same way as rivers, but, being surrounded by high land, have no outlet for the waters so that they may flow back into the sea. If a lake were about to be formed it would be in this way—the rain descending on the surrounding high lands would run in rills to the lowest part, and there collect, forming a pool which would gradually increase in size as the water flowed into it, this increase continuing until the surface became so large that the evaporation from it exactly equalled the supply, it would then extend no further, but remain a permanent lake or inland sea, giving off vapour to refresh the surrounding country, and again receiving it back by streams and rivers, as does the ocean.

There is scarcely a spot known on the surface of the earth, which does not show strong evidence of having, at some former period, been the bed or bottom of some sea or lake. Some of these evidences may be seen in the strata or layers of earth forming the sides of the cliffs which abut on the sea-shore, and which could not have been produced by any other agency; these strata contain so many marine shells and other matters peculiar to the sea, that the fact does not admit of doubt that they were there produced. These same strata are met with throughout the land; in sinking wells and mines, the same strata are cut through, and have a known and uniform succession, with but few exceptions; the cliffs, however, are the most convenient places to see these strata. That the same process of alteration in the position of the water and land is still going forward, is shown by many evidences, such as towns which were once on the sea-shore, being now some distance from it, as the City of Norwich, and in other cases the reverse. The chalk cliffs at Dover, Ramsgate, &c., show the action of the sea in the corroded state they present, and slips or falls of great masses which have been undermined by the sea, are frequently occurring.

CLIFFS, SHOWING STRATA.

The ancient town of Ravenspurn, at which Henry IV. landed, has entirely disappeared, and others, recorded to have been situated on the shore, have now only their names left. The parts of the shore most rapidly corroded by the sea, are those composed of sand, chalk, and clay, while those composed of the harder kinds of sandstone or of granite, have been but little wasted away, so that they project and form the headlands, while in many cases deposits of mud have extended them. There are many other causes which determine the elevation or depression of the land, besides the action of the sea and earthquakes, such as winds, frosts, &c.

CHALK CLIFFS, DOVER.

GREAT WAVES AT SEA.

DEAD CALM

The slightest movement of the air communicates motion to the surface of such a great sheet of water as the sea, and this motion is gradually increased till one ripple meets another, and the power of both goes to form the next, so that they acquire a very considerable size; when a gale of wind blows, the rolling of the waves far out at sea becomes terrific, and they rise like mountains, chasing one another over the wide ocean. But sailors rather like a smart breeze, and more especially did they a few years ago, when the wind was all they had to depend upon for onward progress. In those days a calm which would sometimes last for weeks together was to them most fearful, for it was often a source of great distress and privation, especially if short of provisions; the sea would then look like a great pool of stagnant water covered on the surface with sea-weed and animalculæ, and fearful it must have been when food was failing, and no hope of progressing but the springing-up of a wind. But, in these days, with the assistance of steam, a calm is the very time in which most progress is made, and there is no doubt but a time will come when it will be matter of wonder that men could ever have trusted to so uncertain an element as the wind; yet, if it were not for the winds, currents, and tides, the sea could not maintain its state of purity, for its saltness is not sufficient to prevent the growth of fungi and all sorts of animalculæ, which, from their decay, would produce noxious gases and be most injurious to animal life. Its constant motion alone prevents this, and the spores and germs are tossed about until destroyed and eaten up by the inhabitants of the deep who devour every kind of organic matter which is deposited in the sea, and thus it is that the waters of the ocean are so bright and clear that an object can be seen at a considerable depth.

That the constant currents of the sea prevent the formation and growth of sea-weed, is clearly shown by the great "Sargasso Sea," or tract of weed (Fucus natans), called the Gulf-weed. This great tract embraces thousands of square miles, and is situated in the very middle of the Atlantic Ocean, where there are but few currents; but surrounding it is the Gulf-Stream, an enormous current of water running at a regular rate of four or five miles an hour. This Gulf-Stream is supposed to be caused by the same laws and influences which determine the trade-winds, namely, a constant rarefaction of the water at the tropical parts of the earth, and a corresponding condensation at the Arctic portions, for warm water is much lighter than cold, and when the waters of the tropical regions become lighter the heavier waters of the cold regions pressing down more forcibly tend to raise them above their proper level; they therefore flow towards those very parts which have sunk down by their contraction, and a constant current takes place—this current is the Gulf-Stream. It runs from the Gulf of Mexico northwards towards Newfoundland, turning by Iceland towards the British Isles, by France and Spain, onwards to the coasts of Africa and South America, the West Indies, and again to the Gulf of Mexico, although the return current does not go by the name of Gulf-Stream. This great stream of water warmed by the tropical sun serves the same two purposes described under the section "Air" as being fulfilled by the trade-winds, namely, a circulation and distribution of the superfluous heat of the equatorial regions, warming the northern countries and cooling by the return of under-currents those in the tropics. The fogs of Newfoundland are caused by the great current of warm water entering the cold region and carrying with them surface-currents of moist air, which the cold condenses into fog, just as the breath is visible in a cold atmosphere. England owes its moist and mild climate to the same cause.

The sand which lies upon the sea-shore is produced by the action of the waves constantly dashing against the earth and rocks of the coast, and is mostly composed of what chemists call "silex," or silica, which is a chief constituent of most rocks and earths; these, being worn down by the action of the waters, form sand. The fragments of these rocks (especially granite) and those which contain silica in the form of minute crystals, are soon rolled and rubbed together until they are ground to powder, but it is doubtful whether any sand exists at the bottom of the deep seas far from shore, as the waters there lie—and must have laid—perfectly quiet ever since they were seas, for the greatest storm that ever rages does not affect the tranquility of the sea more than a few fathoms beneath its surface, so that a stone dropped in the middle of the Atlantic Ocean, could be picked up after a hundred years exactly where it fell, were it possible for any to find out the spot and descend; but the bottom of some deep seas, as in the antarctic regions and the north Atlantic Ocean (as the soundings between Ireland and America have lately shown), is covered to an unknown depth with what had been supposed to be sand, but which is not sand at all, but a wonderful collection of minute shells and coralines, which to the unassisted eye have the appearance of sand. They are the silicious shells and coverings of minute vegetables and animals, these creatures, being coated with silica (a substance indestructible by age and the action of water), fall to the bottom of the sea and there accumulate in such countless myriads that they form this fine substance, long mistaken for sand, but between which, in reality, there is a marked distinction, the one being formed by the disintegration and grinding-up of rocks, the other the product of organic life; this, when it has accumulated for ages, will, in all probability, form some island or part of a continent, and be the site perhaps of some magnificent city, reared upon a foundation of these minute wonders of the deep, whose skeletons will have become consolidated into a hard and compact stone, of which its houses and churches will, in all probability, be built.

This is not imagination, as such occurrences have really taken place—all our chalk cliffs and downs constitute part of an immense stratum. Now, every grain of this chalk contains and is made up of thousands of minute shells and corals. These chalk downs were once the bed of some ocean which, in all probability, was filled up by their remains.

What are the railroads and works of men's hands compared with this? Of this chalk (hardened by pressure into limestone) most of our public buildings are constructed, or (changed by pressure and heat into marble) our statues of great men have been carved. What a mockery to choose marble as the medium of rendering our heroes immortal—itself the very type of mortality, being formed by the death of millions of creatures.

In Dr. Carpenter's work on the microscope occurs the following:—

"Thus, when we meet with an extensive stratum of fossilised Diatomaceæ, in what is now dry land, we can entertain no doubt that this silicious deposit originally accumulated either at the bottom of a fresh-water lake or beneath the waters of the ocean, just as some deposits are formed at the present time, by the production and death of successive generations of these bodies, whose indestructible casings accumulate in the lapse of ages, so as to form layers, whose thickness is only limited by the time during which this process has been in action.

"In like manner, when we meet with a limestone rock entirely composed of the calcareous shells of Foraminifera—some of them entire, others broken up into minute particles—we interpret the phenomenon by the fact that the dredgings obtained from certain parts of the ocean-bottom, consist almost entirely of remains of existing Foraminifera, in which entire shells—the animals of which may be yet alive—are mingled with the debris of others that have been reduced by the action of the waves to a fragmentary state.

"Now, in the fine white mud which is brought up from almost every part of the sea-bottom of the Levant, where it forms a stratum that is continually undergoing a slow but steady increase in thickness, the microscopic researches of Professor Williamson have shown that not only are there multitudes of minute remains of living organisms, both animal and vegetable, but that it is entirely or almost wholly composed of such remains."

ORGANISMS FROM MUD.

The water of the sea is everywhere salt, except at the mouths of great rivers, where the quantity of fresh water displaces that which properly belongs to the sea. The cause of its saltness is the solution of a natural mineral (chloride of sodium) which exists in the earth in great abundance in layers of a crystalline structure, and as this chloride of sodium (common salt) is soluble in water, of course it is all dissolved by the water in whatever situation they may come into contact with each other. The composition of sea-water differs slightly in different parts of the earth, the southern seas being slightly more salt than the northern. As a general rule, about five per cent. of solid matter is contained in sea-water, of this rather more than half (5.7) is chloride of sodium; the greater part of the other half consists of different salts of magnesia, and this is the whole source of the medicines known as Epsom salts and magnesia, the former being the sulphate and the latter the carbonate of magnesia. Iodine, another article used in medicine and photography, is also extracted from sea-water, which however contains but a very minute portion, too small to be detected as a general rule, but extracted by burning certain sea-weeds, in the ashes of which it is found in sufficient quantity to be separated.

Although the sea as a whole keeps its level, yet in various parts it is constantly rising and sinking, sometimes at one place and sometimes at another; these risings and fallings are called tides, and are caused by the joint action of the sun and moon, that is, by their attraction, acting at different distances. First it must be observed (as is well known) attraction varies inversely as the square of the distance, that is, if the moon were twice as far off, her attraction of the earth would be one-fourth of what it now is, if three times as far off, one-ninth, and so on.

The moon's average distance from the centre of the earth (A to C, in the diagram) is about 240,000 miles, or about 60 times the earth's radius (B C), which is a little under 4000 miles, consequently if the distance from the moon to the centre of the earth (A C) be expressed by 60, the distance to the nearest surface (A B) will be 59, and the farthest surface (A D) 61. The moon will attract the point B with a force of 1/592 or 1/3481, the point C with the force of 1/602 or 1/3600, and the point D with the force of 1/612 or 1/3721. Now as the force at C is greater than at D, the earth itself will be pulled away from the water at D, and leaving it a little behind, will produce a high tide there, this tide is known as the "inferior tide" (2). Again as the force at B is greater than at C, the water at B will be pulled away from the earth and produce a still higher tide, called the "superior tide" (1), or that which takes place when the moon is due south. This heaping-up of the waters by the moon, to the height of 4½ feet (on an average) causes corresponding depressions to the same depth in those parts of the earth which are situated between the raised parts, making a difference between high and low-water of nine feet due to the moon; precisely the same effects are produced by the sun, but though his attractive power is so much greater than the moon's, his distance is also so much greater, that the heap of water he can raise is somewhat less than 2 feet, and makes therefore less than 4 feet difference between high and low-water, due to the sun. When the sun and moon are both on the same side, or on opposite sides of the earth (as at new or full moon), then the attraction of both act together and produce "spring tides," with a difference of 13 feet; at first and last quarter the sun and moon oppose each other, acting in cross directions, and the difference is then only 5 feet. But these effects could only take place in the wide open space of an ocean, and when other forces do not interfere, such as obstruction to the tide-waves by land, &c.

DIAGRAM OF THE TIDES.

Inland seas (as large as the Mediterranean even) have but very little tide, while pinched-up rivers may have a great rush of tide, as at Bristol, where it rises to 45 feet sometimes, and at Anapolis in Nova Scotia, to so much as 120 feet! Wind will also accelerate or retard both the speed and height of the tides. London receives a much greater tide than its due, for the tidal-wave being interrupted by Ireland and England, rolls up the western coast (taking a northerly direction) with such force as to swing round the Shetlands and all down the eastern coast of Great Britain. The direct Atlantic wave also, when split by our island, rolls along the south coast from Land's-End to Dover, rushes through the "Straits," and meets the backward wave which has been travelling round by Scotland (as before mentioned), the two then pour into the Thames and give an otherwise quiet river a high and useful tide; so that London receives two tides, the southern one nearly 10 hours after Cornwall, and the roundabout one not till nearly 23 hours after it first reaches England.

RIVER THAMES.

The waters are the great highway throughout the whole world, and what an easy transit it has formed to those nations sufficiently civilised to require a further knowledge of the world, and thence procure for themselves luxuries not obtainable at home—at the same time, spreading civilisation wherever they go!

If the oceans, instead of forming one great concourse of waters, had existed in the form of inland seas or great lakes, the great chains of mountains, deserts, and uninhabited tracts of earth, would, in some cases, have formed impassable barriers, whilst in other parts civilisation would have been impeded from the easy access of the more savage tribes, who would have despoiled the more fortunate by inroads amongst them, mingling with or exterminating them, and checking the onward progress of civilisation. And this has always existed where great tracts of land are, which are the last parts of the world to be civilised, and in many parts remain as rude as they were thousands of years ago. All this is owing to the good and wise arrangement of water and land, and is an instance of the care and foreknowledge of God, who has provided for the onward progress of that creature to whom alone such a progress has been allotted; but as they now exist the oceans form impenetrable barriers to the savage, so as to restrict his brute force and uncultivated habits spreading, while they form easily-traversed highways to the more civilised nations, enabling them to spread their civilisation without contamination to themselves, but to the advancement of others.

The oceans are now navigated by thousands of vessels engaged in mercantile objects, and it is perfectly astonishing with what rapidity and safety these great tracts of water are crossed.

In one of Chambers's "Papers for the People," called "Ocean Routes," is the following, speaking of the perfecting of the steam-vessel:—

"The regularity, speed, and safety with which the voyages of these vessels were made, soon pointed them out as the best conveyance both for passengers and the mails.

"In 1821 they were employed on the latter service between Dublin and Holyhead, and between Calais and Dover; and now, with few exceptions, all the channel and ocean-work of the Post-Office is done by steamers, and all the passengers and much of the goods' traffic between the parts of Great Britain and Ireland, have been within the last quarter of a century transferred to them.

"After the steamboat had thus passed through the various stages of infancy and childhood—had tried its strength on English rivers, in the Irish Sea, and in the British Channel—men began to ask, was it not strong enough and old enough to do more? Could it not cross an ocean as well as a channel—take letters and men, and merchandise to America, India, and Australia, as well as to Ireland and France? In this question were involved considerations of the highest importance to all the world, but particularly to this country, for no other country has such extensive foreign possessions as Great Britain, or carries on such an extensive trade.

"With the exception of the United States, all the colonies planted by the British remain parts of the empire, while Spain and Portugal have lost nearly all those rich territories, extending over the fairest portion of the American continent, that at one time acknowledged the sway of the houses of Bourbon and Braganza. The foreign possessions of France are insignificant, and, of the other nations of Europe, the Dutch alone possess a territory abroad greater than they have at home.... The proud position of Britain among the nations, the necessities of her foreign trade, and the wants of her colonies and dependencies, apart from all other considerations, rendered it fitting and natural that she should lead the way in maritime enterprise, and teach the nations how to navigate the ocean by steam.

"Nor has she failed in this high task; for, within thirteen or fourteen years, since the question was first proposed, she has established lines of gigantic steam-vessels that are now traversing with regularity and safety every ocean, steaming altogether more than a million and a quarter miles every year, and distributing letters and newspapers all over the world, at a cost to the country of about £650,000 per annum."

The rapidity and ease with which thousands of troops were lately conveyed to the Crimea and India, together with all their stores, horses, &c., form one of the most wonderful feats of ocean navigation ever performed, and point out the beauty of those arrangements which enable man to traverse the whole earth, whether by land or by water, so that it may fairly be said that the civilisation of the world depended and still depends upon the waters.

INTRODUCTION
TO THE
ORGANIC KINGDOMS OF NATURE.

The foregoing descriptions refer to the great works of God as seen in those creations which possess not that most wonderful attribute—life. There is no limit in extent, in quality, or in number, to these works; their extension appears to be infinite; their magnitudes are large or small, just as we compare them one with the other. This earth is an enormous mass, contemplated in comparison with ourselves, but an insignificant speck when compared with the sun, and there are certain laws, chemical and mechanical, which govern them all—heat, light, and electricity permeate all the infinity of space—attraction exists everywhere. There are no individual existences among them; all are made up of matter combined according to certain definite chemical laws, and always obedient to them under the same conditions—moving according to certain mechanical laws, and always obedient to them. The Creator who made these lifeless masses made also the laws to regulate them; but, besides these, it has pleased Him to form certain other creatures not for an instant to be compared in size or quantity with the former, and made up also of certain chemical compounds obedient to the mechanical and chemical laws, with one more addition, that unknown, inexplicable attribute—life. This wonderful quality exists in all organic beings; they obtain by it individual identity; they are whole creatures—imperfect with any part taken away, also imperfect with any addition. Clay is clay, in any quality or form; iron is iron, whether a grain or a ton; but a tree is only a tree when it is complete. We cannot say "some tree," as we would "some clay," it must be a tree, or several trees, each a separate and complete existence—perfect in itself—made up of solids and fluids, and possessing certain attributes, namely, a constant circulation of its fluid parts, a constant appropriation of food and rejection of waste matters—growth thereby to a certain definite form, and in many a definite size, together with the production of germs, capable, under certain conditions, of producing beings exactly similar to themselves. This constitutes organic life, and is possessed by all vegetables. Animal life is exactly the same, with the super-addition of will or mind in its most perfect state, of instinct or some analogous function in its lower states, or in quite the lowest—a chemical and mechanical difference only, such as shall determine the choice of food and mode of assimilating it. This difference consists in the vegetable feeding upon inorganic food, and the animal on food which has received the stamp of organisation. Creatures possessing life, whether vegetable or animal, are called organisms. It is found that these organisms are made up of certain atoms united in larger multiples than in inorganic substances, which are either simple or compounded of but few atoms; thus water is composed (every atom of it) of one atom oxygen, united to two of hydrogen. Common salt (every atom of it) is composed of one atom of the metal sodium with one atom of chlorine. Chalk is compounded of one atom of calcium in union with one of oxygen, and this united to one atom of carbonic acid, itself composed of one atom of carbon with two of oxygen. But organic compounds are often made up of four or six elements, united in multiples of their usual combining quantities. Thus, grape-sugar is made up (every atom of it) of 24 atoms of carbon, 28 of hydrogen and 28 of oxygen; these 78 atoms unite and form one compound atom, of which the sugar is wholly compounded, and thus, from such a complex nature, it happens that most organic compounds are decomposed by even a moderate degree of heat—all by a heat equal to red-hot iron. From these facts, it may be therefore stated, that all organisms are complete in themselves, have definite lives or existences, appropriate certain matters to themselves, grow thereby, and are compounded of organic atoms.

[THE VEGETABLE KINGDOM.]