Cosmos, Volume 2: Sketch of a Physical Description of the Universe (Cambridge Library Collection - Physical Sciences)

Cambridge Library CoLLeCtion Books of enduring scholarly value

Physical Sciences From ancient times, humans have tried to understand the workings of the world around them. The roots of modern physical science go back to the very earliest mechanical devices such as levers and rollers, the mixing of paints and dyes, and the importance of the heavenly bodies in early religious observance and navigation. The physical sciences as we know them today began to emerge as independent academic subjects during the early modern period, in the work of Newton and other ‘natural philosophers’, and numerous sub-disciplines developed during the centuries that followed. This part of the Cambridge Library Collection is devoted to landmark publications in this area which will be of interest to historians of science concerned with individual scientists, particular discoveries, and advances in scientific method, or with the establishment and development of scientific institutions around the world.

Cosmos Polymath Alexander von Humboldt (1769-1859), a self-described ‘scientific traveller’, was one of the most respected scientists of his time. Humboldt’s wanderlust led him across Europe and to South America, Mexico, the U.S. and Russia, and his voyages and observations resulted in the discovery of many species previously unknown to Europeans. Originating as lectures delivered in Berlin and Paris (1827–8), his two-volume Cosmos: Sketch of a Description of the Universe (1845–60) represented the culmination of his lifelong interest in understanding the physical world. As Humboldt writes, ‘I ever desired to discern physical phenomena in their widest mutual connection, and to comprehend Nature as a whole, animated and moved by inward forces’. Volume 2 (1848) reviews poetic descriptions of nature as well as landscape painting from antiquity through to modernity, before using the same time-span to examine a ‘History of the Physical Contemplation of the Universe’.

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Cosmos Sketch of a Physical Description of the Universe Volume 2 A l exander von Humb oldt E dited by E dward Sabine

C A M B R I D g E U N I V E R SI t y P R E S S Cambridge, New york, Melbourne, Madrid, Cape town, Singapore, São Paolo, Delhi, Dubai, tokyo Published in the United States of America by Cambridge University Press, New york www.cambridge.org Information on this title: www.cambridge.org/9781108013642 © in this compilation Cambridge University Press 2010 This edition first published 1848 This digitally printed version 2010 ISBN 978-1-108-01364-2 Paperback This book reproduces the text of the original edition. The content and language reflect the beliefs, practices and terminology of their time, and have not been updated. Cambridge University Press wishes to make clear that the book, unless originally published by Cambridge, is not being republished by, in association or collaboration with, or with the endorsement or approval of, the original publisher or its successors in title.

COSMOS: SKETCH OF A

PHYSICAL DESCRIPTION OF THE UNIVERSE. BY

ALEXANDER VON HUMBOLDT. VOL. I. Nettira two rerum vis atque mqjestas in omnibus mrmentisfide caret, si fyia'i motlo ),fn-trs rju ac non totam complectatur animo.—PLIN. H. N. lib. vii. c. 1.

TRANSLATED UNDER THE SUPERINTENDENCE OF

LIEUT.-COL. EDWARD SABINE, R.A., FOR. SEC. R.S.

LONDON: PRINTED FOR

LONGMAN, BROWN, GREEN, AND LONGMANS, PATERNOSTER ROW ; AND

JOHN MURRAY, ALBEMARLE STREET. 1846.

EDITOR'S PREFACE.

THIS translation of Cosmos was undertaken in compliance with the wish of Baron von Humboldt.

The Editor, in

common he believes with many others, is indebted to the earlier writings of the Author of Cosmos, for awakening in his mind a taste for pursuits, which have formed a, large portion of his interest and added greatly to his enjoyment in life: long cherished feelings of gratitude for this obligation, combined with those of personal regard, have been motives with himself, and with Mrs. Sabine,—by whom the Translation has been made,—to surmount the hesitation which they might otherwise have felt in venturing On a task embracing so extensive a range of subjects.

Should this

translation be favourably received, it will be a great gratification to them hereafter to reflect, that they have been instrumental in making known to the English reader, the work in which the illustrious Author has embodied the fruits of his active and useful life.

Vlii

EDITOR S PREFACE.

The two introductory discourses, which occupy 48 pages in the German edition, have been rewritten by M. de Humboldt himself in the French language, for the Trench edition, in which they fill 78 pages.

These were commu-

nicated to the Editor in their passage through the press, and by the Author's desire have been followed in preference to the corresponding portion of the German text, where modifications or additions had been introduced. Short as the interval has been since Cosmos was written, it has not been unmarked by the progress which has been made in several branches of scientific knowledge.

In

astronomy it has been distinguished by the discovery of a new planet, Astrea, making the number of those bodies belonging to our solar system twelve instead of eleven: also of the two heads of Biela's comet, a phsenomenon previously unknown.

These discoveries, however, in no

respect affect the reasonings in Cosmos.

The optical

means at the command of astronomers have also been improved, by the construction of a telescope of unparalleled dimensions by the Earl of Rosse; and the few trials which have yet been made of its powers, lead to the belief, that the greater part, if not the whole, of the nebulae will be resolved by it into stars : happily the Author of Cosmos will himself have an opportunity, in the succeeding volumes, of stating the influence which a discovery of this nature may exercise

EDITOR S PREFACE.

IX

upon the view which has been taken of the Celestial Phsenomena in the volume now published. .It has been M. de Humboldt's wish, and kindly pressed by him, that the Editor should add such notes as he might think desirable, particularly in the branches of science in which he has himself engaged: he has felt the propriety of exercising this privilege very sparingly, and has only availed himself of it in additions to Notes 132, 136, 139, 143, 158, 179, 373, and 382. Measures of itinerary distance are expressed in the original work in geographical miles of 15 to the degree ; these have been converted in the translation into geographical miles of 60 to the degree, as more consonant to English usage.

Measures of length are expressed by M. de Hum-

boldt usually in French feet and toises, which have been retained in the translation; but the equivalent values in English feet have been added whenever it has appeared desirable to do so.

In like manner the measures of tempera-

ture in Fahrenheit's scale have been given in addition to those in the Centesimal scale.

WOOLWICH, AUG. 22,

1846.

a 2

TO HIS MAJESTY

THE

KING

FRIEDRICH-WILHELM IV. THIS SKETCH OF A PHYSICAL DESCRIPTION OF THE UNIVERSE

IS DEDICATED, WITH PROFOUND KESPECT AND HEARTFELT GRATITUDE,

BY

ALEXANDER VON HUMBOLDT.

CONTENTS.

Page ivii

THE AUTHOR'S PREFACE

INTRODUCTION. O n the different degrees of enjoyment offered by t h e aspect of N a t u r e and t h e study of her laws . . . . . . . . 3 Limits a n d m e t h o d of exposition of t h e Physical description of t h e universe . . . . . . . . . . . 42

GENERAL VIEW O F NATURE. Introduction

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. 6 7

CELESTIAL P H E N O M E N A .

Nebulse Sidereal systems O u r sidereal system T h e solar system . Planets Satellites Comets Aerolites Zodiacal light

. .

. .

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. .

73 77 79 81 82 86 91 105 127

xiv

CONTENTS. Page

The sun P r o p e r m o t i o n s of s t a r s . . . . • Double and multiple stars D i s t a n c e s , m a s s e s , a n d a p p a r e n t d i a m e t e r s of s t a r s . V a r i a b l e a s p e c t of t h e h e a v e n s Nebulous milky-way Successive p r o p a g a t i o n of l i g h t . . . . . TERRESTRIAL

134

• .

.

. l o o 136 . 137 138 141 143

PHENOMENA.

G e n e r a l view . . . . Figure of the earth D e n s i t y of t h e e a r t h I n t e r n a l h e a t of t h e e a r t h M e a n t e m p e r a t u r e of t h e e a r t h Terrestrial magnetism . Polar light, o r aurora .

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R e a c t i o n of t h e i n t e r i o r of t h e e a r t h o n i t s e x t e r i o r Earthquakes E r u p t i o n s of g a s H o t a n d cold s p r i n g s M u d volcanoes Volcanoes . . . . . . .

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145 154 159 . - 1 6 1 . 164 . . 1 6 7 179 .

.

.

. 189 191 205 207 211 213

Geological description of t h e e a r t h ' s c r u s t 235 F u n d a m e n t a l classification of r o c k s . . . . . 236 Endogenous or erupted rocks . . . . . . 238 Exogenous o r sedimentary rocks . . . . . 2 4 1 Metamorphic rocks 244 Artificial p r o d u c t i o n of s i m p l e m i n e r a l s . . . . 2 5 6 Conglomerates . . . . . . . . 257 G e n e r a l c h e m i c a l c o n s t i t u e n t s of r o c k s . . . . 258 Palaeontology—Fossil organic remains 260 Palseozoology—Fossil animals 261 Palffiophytology—Fossil p l a n t s 268 P a l s e o g e o g r a p h y — S t a t e of t h e surface of t h e g l o b e a t different geological epochs 274

CONTENTS.

XV Page

Physical Geography—General view Thelana The ocean The atmosphere—Meteorology. . . . Atmospheric pressure . . . . . . Climatology L i m i t of p e r p e t u a l s n o w . . . . . Hygrometry Atmospherical electricity . . . . . . M u t u a l d e p e n d e n c e of m e t e o r o l o g i c a l p h s e n o m e n a

278 280 294 . . 3 0 4 . 308 312 . . 3 2 7 330 . 333 . . 336

ORGANIC LIFE.

General view G e o g r a p h y of p l a n t s a n d a n i m a l s Man

NOTES

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338 345 350

361

AUTHOR'S PREFACE.

Ix the late evening of a varied and active life, I offer to the German public a work of which the undefined type has been present to my mind for almost half a century.

Often the

scheme has been relinquished as one which I could not hope to realise, but ever after being thus abandoned, it has been again, perhaps imprudently, resumed.

In now presenting

its fulfilment to my contemporaries, with that hesitation which a just diffidence of my own powers could not fail to inspire, I would willingly forget that writings long expected are usually least favourably received. While the outward circumstances of my life, and an irresistible impulse to the acquisition of different kinds of knowledge, led me to occupy myself for many years, apparently exclusively, with separate branches of science,—descriptive botany, geology, chemistry, geographical determinations, and terrestrial magnetism, tending to render useful the ex-

xviii

ATJTHOB'S JREFACE.

tensive journeys in which I engaged,—I had still throughout a higher aim in view; I ever desired to discern physical phsenomena in their widest mutual connection, and to comprehend Nature as a whole, animated and moved by inward forces.

Intercourse with highly-gifted men had early led me

to the conviction, that without earnest devotion to particular studies such attempts could be but vain and illusory.

The

separate branches of natural knowledge have a real and intimate connection, which renders these special studies capable of mutual assistance and fructification : descriptive botany, no longer restricted to the narrow circle of the determination of genera and of species, leads the observer, who traverses distant countries and lofty mountains, to the study of the geographical distribution of plants according to distance from the equator and elevation above the level of the sea.

Again, in order to elucidate the complicated causes

which determine this distribution, we must investigate the laws which regulate the diversities of climate and the meteorological processes of the atmosphere; and thus the observer, earnest in the pursuit of knowledge, is led onwards from one class of phsenomena to another, by their mutual connection. I have enjoyed one advantage which few scientific travellers have shared to an equal degree, in having seen not merely coasts, and districts little removed from the margin of the ocean, as in voyages of circumnavigation,—but in having,

AUTHOR S PREFACE.

xix

moreover, traversed, both in the new and the old world, extensive continental districts presenting the most striking contrasts; on the one hand the tropical and alpine landscapes of Mexico and South America, and on the other the dreary uniformity of the steppes of Northern Asia.

Such oppor-

tunities could not fail to encourage the tendencies of a mind predisposed to generalisation, and were well fitted to animate me to the attempt of treating in a special work our present knowledge of the sidereal and teirestrial phsenomena of the universe in their empirical connection.

" Physical Geogra-

phy,'" the limits of which have been hitherto somewhat vaguely defined, has been thus expanded, by perhaps too bold a plan, into a scheme comprehending the whole material creation, or into that of a " Physical Cosmography." Such a work, if it would aspire to combine with scientific accuracy any measure of success as a literary composition, has to surmount great difficulties, arising from the very abundance of the materials which the presiding mind must reduce to order and clearness, while yet the descriptions of the varied forms and phenomena of nature must not be deprived of the characteristic traits which give them life and animation. A series of general results would be no less wearisome than a mere accumulation of detached facts.

I cannot venture to

flatter myself that I have adequately satisfied these various conditions, or avoided the dangers which I have not failed

xx

AUTHOR'S PREFACE.

to perceive; the faint hope which I cherish of success rests on the particular favour which my countrymen have long bestowed on a small work which I published, soon after my return from Mexico, under the title of Ansichten der Natur, and which treated some portions of physical geography, such as the physiognomy of plants, savannahs, deserts, and cataracts, under general points of view.

Doubtless the effect

which this small volume produced was far more attributable to its indirect action, in awakening the faculties of young and susceptible minds endowed with imaginative power, than to any thing which it could itself impart.

In my present

work, as in the one to which I have just alluded, I have endeavoured to show practically, that a certain degree of scientific accuracy in the treatment of natural facts is not incompatible with animated and picturesque representation. Public discourses or lectures have always appeared to me well adapted to test the success or failure of an endeavour to unite detached branches of a general subject in a systematic whole; with this view a series of lectures on the Physical description of the Universe, as I had conceived it, was delivered both in Berlin and in Paris, in German and in French.

These discourses were not committed to writ-

ing ; and even the notes preserved by the diligence of some attentive auditors have remained unknown to me; nor have I chosen to have recourse to them in the execution of the

AUTHOR S PREFACE.

XXI

present work, the whole of which, with the exception of a portion of the Introduction, was written for the first time in the years 1843 and 1844; the discourses in Berlin having been delivered from November 1827 to April 1828, previous to my departure for Northern Asia.

A represen-

tation of the actual state of our knowledge, in which year by year the acquisition of new observations imperatively demands the modification of previous opinions, must, as it appears to me, gain in unity, freshness, and spirit, by being definitely connected with some one determinate epoch. The first volume contains a general view of nature, from the remotest nebulse and revolving double stars to the terrestrial phenomena of the geographical distribution of plants, of animals, and of races of men; preceded by some preliminary considerations on the different degrees of enjoyment offered by the study of nature and the knowledge of her laws; and on the limits and method of a scientific exposition of the physical description of the Universe.

I

regard this as the most important and essential portion of my undertaking, as manifesting the intimate connection of the general with the special, and as exemplifying in form and style of composition, and in the selection of the results taken from the mass of our experimental knowledge, the spirit of the method in which I have proposed to myself to conduct the whole work.

In the two succeeding volumes

xxii

AUTHOR'S PREFACE.

I design to consider some of the particular incitements to the study of Nature,—to treat of the history of the contemplation of the physical universe, or the gradual development of the idea of the concurrent action of natural forces co-operating in all that presents itself to our observation,— and lastly, to notice the specialities of the several branches of science, of which the mutual connection is indicated in the general view of nature in the present volume.

References

to authorities, together with details of observation, have been placed at the close of each volume, in the form of Notes. In the few instances in which I have introduced extracts from the works of my friends, they are indicated by marks of quotation; and I have preferred the practice of giving the identical words to any paraphrase or abridgment.

The deli-

cate and often contested questions of discovery and priority, so dangerous to introduce in an uncontroversial work, are rarely touched upon : the occasional references to classical antiquity, and to that highly favoured transition period marked by the great geographical discoveries of the fifteenth and sixteenth centuries, have had for their principal motive, the wish, which is occasionally felt when dwelling on general views of nature, to escape from the more severe and dogmatical restraint of modern opinions, into the free and imaginative domain of earlier presentiments. It has sometimes been regarded as a discouraging consi-

AUTHOR S PREFACE.

XX1U

deration, that whilst works of literature, being fast rooted in the depths of human feeling, imagination, and reason, suffer little from the lapse of time, it is otherwise with works which treat of subjects dependent on the progress of experimental knowledge.

The improvement of instruments,

and the continued enlargement of the field of observation, render investigations into natural phaenomena and physical laws liable to become antiquated, to lose their interest, and to cease to be read.

Such reflections are not entirely desti-

tute of foundation; yet none who are deeply penetrated with a true and genuine love of nature, and with a lively appreciation of the true charm and dignity of the study of her laws, can ever view with discouragement or regret that which is connected with the enlargement of the boundaries of our knowledge.

Many and important portions of this

knowledge, both as regards the phsenomena of the celestial spaces and those belonging to our own planet, are already based on foundations too firm to be lightly shaken; although in other portions, general laws will doubtless take the place of those which are more limited in their application, new forces will be discovered, and substances considered as simple will be decomposed, whilst others will become known.

I venture, then, to indulge the hope, that the

present attempt to trace in animated characters such a general view of the grandeur of nature, and of the perma-

XXIV

AUTHOR S PREFACE.

nent relations and laws discernible through apparent fluctuation, as the knowledge of our own age permits us to form, will not be wholly disregarded even at a future period.

POTSDAM, NOV. 1844.

BRJUTJ. Page 59, line 5, for