Cosmos: A Sketch of the Physical Description of the Universe, Vol. 1

by Alexander von Humboldt

If we except the small asteroids, which appear to us under the forms of aerolites and shooting stars, the regions of space have hitherto presented to our direct observation physical phenomena alone; and in the case of these, we know only with certainty the effects depending upon the quantitative relations of matter of the distribution of masses. The phenomena of the regions of space may consequently be considered as influenced by simple dynamical laws — the laws of motion.

The effects that may arise from the specific difference and the hererogeneous nature of matter have not hitherto entered into our calculations of the mechanism of the heavens. The only means by which the inhabitants of our planet can enter into relation with the matter contained within the regions of space, whether existing in scattered forms or united into large spheroids, is by the phenomena of light, the propagation of the force of gravitation or the attraction of masses. The existence of a periodical action of the sun and moon on the variations of terrestrial magnetism is even at the present day extremely problematical. We have no direct experimental knowledge regarding the properties and specific qualities of the masses circulating in space, or of the matter of which they are probably composed, if we except what may be derived from the fall of aerolites or meteoric stones, which, as we have already observed, enter within the limits of our terrestrial sphere. It will be sufficient here to remark, that the direction and the excessive velocity of projection (a velocity wholly planetary) manifested by these masses, render it more than probable that p 64 they are small celestial bodies, which, being attracted by our planet, are made to deviate from their original course, and thus reach the earth enveloped in vapors, and in a high state of actual incandescence. The familiar aspect of these asteroids, and the analogies which they present with the minerals composing the earth's crust, undoubtedly afford ample grounds for surprise,* but, in my opinion, the only conclusion to be drawn from these facts is that, in general, planets and other sidereal masses, which by the influence of a central body, have been agglomerated into rings of vapor, and subsequently into spheroids, being integrant parts of the same system, and having one common origin, may likewise be composed of substances chemically identical.

[footnote] I[The analysis of an aerolite which fell a few years since in Maryland, United States, and was examined by Professor Silliman, of New Haven, Connecticut, gave the following results: Oxyd of iron, 24; oxyd of nickel, 1.25; silica, with earthy matter, 3.46; sulphur, a trace - 28.71. Dr. Mantell's 'Wonders of Geology', 1848, vol. i., p. 51.] — 'Tr.'

Again, experiments with the pendulum, particularly those prosecuted with such rare precision by Bessel, confirm the Newtonian axiom, that bodies the most heterogeneous in their nature (as water, gold, quartz, granular limestone, and different masses of aerolites) experience a perfectly similar degree of acceleration from the attraction of the earth. To the experiments of the pendulum may be added the proofs furnished by purely astronomical observations. The almost perfect identity of the mass of Jupiter, deduced from the influence exercised by this stupendous planet on its own satellites, on Enck's comet of short period, and on the small planets Vesta, Juno, Ceres, and Pallas, indicates with equal certainty that within the limits of actual observation attraction is determined solely by the quantity of matter.*

[footnote] *Poisson, 'Connaissances des Temps pour l'Anne' 1836, p. 64-66. Bessel, Poggendorf's 'Annalen', bd. xxv., s. 417. Encke, 'Abhandlungen der Berliner Academie' (Trans. of the Berlin Academy), 1826, s. 257. Mitscherlich, 'Lehrbuch der Chemie' (Manual of Chemistry), 1837 bd. i. s. 352.

This absence of any perceptible difference in the nature of matter, alike proved by direct observation and theoretical deductions, imparts a high degree of simplicity to the mechanism of the heavens. The immeasurable extent of the regions of space being subjected to laws of motion alone, the sidereal portion of the science of the Cosmos is based on the pure and abundant source of mathematical astronomy, as is the terrestrial portion on physics, chemistry, and organic morphology; but the domain of these three last-named sciences embraces p 65 the consideration of phenomena which are so complicated and have, up to the present time, been found so little susceptible of the application of rigorous method, that the physical science of the earth can not boast of the same certainty and simplicity in the exposition of facts and their mutual connection which characterize the celestial portion of the Cosmos. It is not improbable that the difference to which we allude may furnish an explanation of the cause which, in the earliest ages of intellectual culture among the Greeks, directed the natural philosophy of the Pythagoreans with more ardor to the heavenly bodies and the regions of space than to the earth and its productions, and how through Philolaus, and subsequently through the analogous views of Aristarchus of Samos, and of Seleucus of Erythrea, this science has been made more conducive to the attainment of a knowledge of the true system of the world than the natural philosophy of the Ionian school could ever be to the physical history of the earth. Giving but little attention to the properties and specific differences of matter filling space, the great Italian school, in its Doric gravity, turned by preference toward all that relates to measure, to the form of bodies, and to the number and distances of the planets,* while the Ionian physicists directed their attention to the qualities of matter, its true or supposed metamorphoses, and to relations of origin.

[footnote] *Compare Otfried Muller's 'Dorien', bd. i., s. 365.

It was reserved for the powerful genius of Aristotle, alike profoundly speculative and practical to sound with equal success the depths of abstraction and the inexhaustible resources of vital activity pervading the material world.

Several highly distinguished treatises on physical geography are prefaced by an introduction, whose purely astronomical sections are directed to the consideration of the earth in its planetary dependence, and as constituting a part of that great system which is animated by one central body, the sun. This course is diametrically opposed to the one which I propose following. In order adequately to estimate the dignity of the Cosmos, it is requisite that the sidereal portion, termed by Kant the 'natural history of the heavens', should not be made subordinate to the terrestrial. In the science of the Cosmos, according to the expression of Aristarchus of Samos, the pioneer of the Copernican system, the sun, with its satellites, was nothing more than one of the innumerable stars by which space is occupied. The physical history of the world must, therefore, begin with the description of the heavenly bodies, p 66 and with a geographical sketch of the universe, or, I would rather say, a true 'map of th world', such as was traced by the bold hand of the elder Herschel. If, notwithstanding the smallness of our planet, the most considerable space and the most attentive consideration be here afforded to that which exclusively concerns it, this arises solely from the disproportion in the extent of our knowledge of that which is accessible and of that which is closed to our observation. This subordination of the celestial to the terrestrial portion is met with in the great work of Bernard Varenius,* which appeared in the middle of the seventeenth century.

[Footnote] *'Geographia Generalis in qua affectiones generales telluris explicantur.' The oldest Elzevir edition bears date 1650, the second 1672, and the third 1681; these were published at Cambridge, under Newton's supervision. This excellent work by Varenius is, in the true sense of the words, a physical description of the earth. Since the work 'Historia Natural de las Indias', 1590, in which the Jesuit Joseph de Acosta sketched in so masterly a manner the delineation of the New Continent, questions relating to the physical history of the earth have never been considered with such admirable generality. Acosta is richer in original observations, while Varenius embraces a wider circle of ideas, since his sojourn in Holland, which was at that period the center of vast commercial relations, had brought him in contact with a great number of well-iinformed travelers. 'Generalis sive Universalis Geographia dictur quae tellurem in genere considerat atque affectiones explicat, non habita particularium regionum ratione.' The general description of the earth by Varenius ('Pars Absoluta', cap. i.-xxii.) may be considered as a treatise of comparative geography, if we adopt the term used by the author himself ('Geographia Comparativa', cap. xxxiii.-xl.), although this must be understood in a limited acceptation. We may cite the following among the most remarkable passages of this book: the enumeration of the systems of mountains; the examination of the relations existing between their directions and the general form of continents (p. 66, 76, ed. Cantab., 1681); a list of extinct volcanoes, and such as were still in a state of activity; the discussion of facts relative to the general distribution of islands and archipelagoes (p. 220); the depth of the ocean relatively to the height of neighboring coasts (p. 103); the uniformity of level observed in all open seas (p. 97); the dependence of currents on the prevailing winds; the unequal saltness of the sea; the configuration of shores (p. 139); the direction of the winds as the result of differences of temperature, etc. We may further instance the remarkable considerations of Varenius regarding the equinoctial current from east to west, to which he attributes the origin of the Gulf Stream, beginning at Cape St. Augustin, and issuing forth between Cuba and Florida (p. 140). Nothing can be more accurate than his description of the current which skirts the western coast of Africa, between Cape Verde and the island of Fernando Po in the Gulf of Guinea. Varenius explains the formation of sporadic islands by supposing them to be "the raised bottom of the sea:" 'magna spirituum inclusorum vi, sicut aliquando montes e terra protusos esse quidam scribunt' (p. 225). The edition published by Newton in 1681 ('auctior et emendatior' unfortunately contains no additions from this great authority; and there is not even mention made of the polar compression of the globe, although the experiments on the pendulum by Richer had been made nine years prior to the appearance of the Cambridge edition. Newton's 'Principia Mathematica Philosophie Naturalis' were not communicated in manuscript to the Royal Society until April, 1686. Much uncertainty seems to prevail regarding the birth-place of Varenius. Jaecher says it was England, while, according to 'La Biographie Universelle' (b.xlvii., p. 495), he is stated to have been born at Amsterdam; but it would appear, from the dedicatory address to the burgomaster of that city (see his 'Geographia Comparativa', that both suppositions are false. Varenius expressly says that he had sought refuge in Amsterdam, "because his native city had been burned and completely destroyed during a long war," words which appear to apply to the north of Germany, and to the devastations of the Thirty Years' War. In his dedication of another work, 'Descriptio regni Japoniae' (Amst., 1649), to the Senate of Hamburgh, Varenius says that he prosecuted his elementary mathematical studies in the gymnasium of that city. There is, therefore, every reason to believe that this admirable geographer was a native of Germany, and was probably born at Luneburg ('Witten. Mem. Theol.', 1685, p. 2142; Zedler, 'Universal Lexicon', vol. xlvi., 1745, p. 187).