How to Make Hand Fire Grenades.—Make your hand grenades. Fill ordinary quart wine bottles with a saturated solution of common salt, and place them where they will do the most good in case of need. They will be found nearly as serviceable as the expensive hand grenades you buy. Should a fire break out, throw them with force sufficient to break them into the center of the fire. The salt will form a coating on whatever object the water touches, and make it nearly incombustible, and it will prove effectual in many cases, where a fire is just starting, when the delay in procuring water might be fatal.
How the Kind of White Metal is Made That is Used in the Manufacture of Cheap Table Ware.—How same can be hardened and still retain its color? The following are formulas for white metal. Melt together: (a) Tin 82, lead 18, antimony 5, zinc 1, copper 4 parts. (b) Brass 32, lead 2, tin 2, zinc 1 part. For a hard metal, not so white, melt together bismuth 6 parts, zinc 3 parts, lead 13 parts. Or use type metal—lead 3 to 7 parts, antimony 1 part.
What Metal Expands Most, for the Same Change in Temperature?—For one degree Centigrade the following are coefficients of linear expansion: aluminum, 0.0000222; silver, 0.0000191 to 0.0000212; nickel. 0.0000128; copper, 0.0000167 to 0.0000178; zinc, 0.0000220 to 0.0000292; brass, 0.0000178 to 0.0000193; platinum, 0.0000088.
Heavy Timbers.—There are sixteen species of trees in America, whose perfectly dry wood will sink in water. The heaviest of these is the black iron wood (confalia feriea) of Southern Florida, which is more than 30 per cent. heavier than water. Of the others, the best known are lignum vitæ (gualacum sanctum) and mangrove (chizphora mangle). Another is a small oak (quercus gsisea) found in the mountains of Texas, Southern New Mexico and Arizona, and westward to the Colorado desert, at an elevation of 5,000 to 10,000 feet. All the species in which the wood is heavier than water belong to semi-tropical Florida or the arid interior Pacific region.
Highest Point Reached by Man was by balloon 27,000 feet. Travelers have rarely exceeded 20,000 feet, at which point the air from its rarity is very debilitating.
Has a Rate of Speed Equal to Ninety Miles an Hour, ever Been Attained by Railroad Locomotive?—It is extremely doubtful if any locomotive ever made so high a speed. A mile in 48 seconds is the shortest time we have heard of. A rate of 70 to 75 miles per hour has been made on a spurt, on good straight track. The Grant Locomotive Works could make such an engine. Sixty miles an hour for a train is considered a very high rate of speed, and is seldom attained in practice for more than a short run.
The Fastest Boat in the World.—Messrs. Thornycroft & Co., of Chiswick, in making preliminary trials of a torpedo boat built by them for the Spanish navy, have obtained a speed which is worthy of special record. The boat is twin-screw, and the principal dimensions are: Length 147 ft. 6 in., beam 14 ft. 6 in., by 4 ft. 9 in. draught. On a trial at Lower Hope, on April 27, the remarkable mean speed of 26.11 knots was attained, being equal to a speed of 30.06 miles an hour, which is the highest speed yet attained by any vessel afloat.
Staining and Polishing Mahogany.—Your best plan will be to scrape off all the old polish, and well glass paper; then oil with linseed oil both old and new parts. To stain the new pieces, get half an ounce of bichromate of potash, and pour a pint of boiling water over it; when cold bottle it. This, used with care, will stain the new or light parts as dark as you please, if done as follows:—wipe off the oil clean, and apply the solution with a piece of rag, held firmly in the hand, and just moistened with the stain. Great care is required to prevent the stain running over the old part, for any place touched with it will show the mark through the polish when finished. You can vary the color by giving two or more coats if required. Then repolish your job altogether in the usual way. Should you wish to brighten up the old mahogany, use polish dyed with Bismarck brown as follows:—Get three pennyworth of Bismarck brown, and put it into a bottle with enough naphtha or methylated spirits to dissolve it. Pour a few drops of this into your polish, and you will find that it gives a nice rich red color to the work, but don't dye the polish too much, just tint it.
Value of Eggs for Food and Other Purposes.—Every element that is necessary to the support of man is contained within the limits of an egg shell, in the best proportions and in the most palatable form. Plain boiled, they are wholesome. It is easy to dress them in more than 500 different ways, each method not only economical, but salutary in the highest degree. No honest appetite ever yet rejected an egg in some guise. It is nutriment in the most portable form, and in the most concentrated shape. Whole nations of mankind rarely touch any other animal food. Kings eat them plain as readily as do the humble tradesmen. After the victory of Muhldorf, when the Kaiser Ludwig sat at a meal with his burggrafs and great captains, he determined on a piece of luxury—"one egg to every man, and two to the excellently valiant Schwepperman." Far more than fish—for it is watery diet—eggs are the scholar's fare. They contain phosphorus, which is brain food, and sulphur, which performs a variety of functions in the economy. And they are the best of nutriment for children, for, in a compact form, they contain everything that is necessary for the growth of the youthful frame. Eggs are, however, not only food—they are medicine also. The white is the most efficacious of remedies for burns, and the oil extractable from the yolk is regarded by the Russians as an almost miraculous salve for cuts, bruises and scratches. A raw egg, if swallowed in time, will effectually detach a fish bone fastened in the throat, and the white of two eggs will render the deadly corrosive sublimate as harmless as a dose of calomel. They strengthen the consumptive, invigorate the feeble, and render the most susceptible all but proof against jaundice in its more malignant phase. They can also be drunk in the shape of that "egg flip" which sustains the oratorical efforts of modern statesmen. The merits of eggs do not even end here. In France alone the wine clarifiers use more than 80,000,000 a year, and the Alsatians consume fully 38,000,000 in calico printing and for dressing the leather used in making the finest of French kid gloves. Finally, not to mention various other employments for eggs in the arts, they may, of course, almost without trouble on the farmer's part, be converted in fowls, which, in any shape, are profitable to the seller and welcome to the buyer. Even egg shells are valuable, for aliopath and homeopath alike agree in regarding them as the purest of carbonate of lime.
History of Big Ships.—In the history of mankind several vessels of extraordinary magnitude have been constructed, all distinctively styled great, and all unfortunately disastrous, with the honorable exception of Noah's Ark. Setting aside this antediluvian craft, concerning the authenticity of whose dimensions authorities differ, and which, if Biblical measures are correct, was inferior in size to the vessel of most importance to modern shipowners, the great galley, constructed by the great engineer Archimedes for the great King Hiero II., of Syracuse, is the first illustration. This ship without a name (for history does not record one) transcended all wonders of ancient maritime construction. It abounded statues and painting, marble and mosaic work. It contained a gymnasium, baths, a garden, and arbored walks. Its artillery discharged stones of 3 cwt., and arrows 18 ft. in length. An Athenian advertising poet, who wrote a six-line puff of its glories, received the royal reward of six thousand bushels of corn. Literary merit was at a higher premium in the year 240 B.C., than it is to-day. The great ship of antiquity was found to be too large for the accommodation of the Syracusan port, and famine reigning in Egypt, Hiero, the charitably disposed, embarked a cargo of ten thousand huge jars of salted fish, two million pounds of salted meat, twenty thousand bundles of different clothes, filled the hold with corn, and consigned her to the seven mouths of the Nile, and since she weighed anchor nothing more has been heard of her fate. The next great ship worthy of mention is the mythical Saracen encountered in the Mediterranean Sea by the crusading fleet of Richard Coeur de Lion, Duke of Guienne and King of England, which, after much slaughter and damage incident to its infidel habit of vomiting Greek fire upon its adversaries, was captured and sunk. Next in rotation appears the Great Harry, built by Henry VIII., of England, and which careened in harbor during the reign of his successor, under similar circumstances to those attending the Royal George in 1782—a dispensation that mysteriously appears to overhang a majority of the ocean-braving constructions which, in defiance of every religious sailor's superstition that the lumber he treads is naturally female, are christened by a masculine or neutral title. In the year 1769, Mark Isambard Brunel, the Edison of his age, as his son was the Ericsson of that following, permitted himself to be born at Hacqueville; near Rouen, France, went to school, to sea, and into politics; compromised himself in the latter profession, and went to America in 1794, where he surveyed the canal now connecting Lake Champlain with the Hudson River at Albany, N.Y. There he turned architect, then returned to Europe, settled, married, and was knighted in England. He occupied eighteen years of his life in building an unproductive tunnel beneath the river Thames at London; invented a method of shuffling cards without using the hands, and several of her devices for dispensing with labor, which, upon completion, were abandoned from economical motives. On his decease, his son and heir, I.K. Brunel, whose practical experience in the Thames Tunnel job, where his biographers assert he had occasion more than once to save his life by swimming, qualified him to tread in his father's shoes, took up his trade. Brunel, Jr., having demonstrated by costly experiments, to the successful proof, but thorough exasperation, of his moneyed backers, that his father's theory for employing carbonic acid gas as a motive power was practicable enough, but too expensive for anything but the dissipation of a millionaire's income, settled down to the profession of engineering science, in which he did as well as his advantages of education enabled him. Like all men in advance of their time, when he considered himself the victim of arbitrary capitalists ignoring the bent of his genius, he did his best work in accordance with their stipulations. He designed the Great Western, the first steamship (paddle-wheel) ever built to cross the Atlantic; and the Great Britain, the original ocean screw steamer. Flushed with these successes, Brunei procured pecuniary support from speculative fools, who, dazzled by the glittering statistical array that can be adduced in support of any chimerical venture, the inventor's repute, and their unbaked experience, imagined that the alluring Orient was ready to yield, like over-ripe fruit, to their shadowy grasp; and tainted as he evidently was with hereditary mania, Brunel resolved to seize the illusionary immortality that he fondly imagined to be within his reach. There was not much the matter with the brain of Brunel, Jr., but that little was enough; a competent railroad surveyor, a good bridge builder, he needed to be held within bounds when handling other people's funds; for the man's ambition would have lead him to undertake to bridge the Atlantic. He met with the speculators required in this very instance of the constructors of the Great Eastern. This monstrous ship has been described so often, that it would be a cruelty to our readers to inflict the story upon them again.