Physiography : an introduction to the study of nature

Introduction

TO THE STUDY OF NATURE. BY T. H. HUXLEY, F.R.S. IVITH ILLUSTRATIONS AND COLOURED PLATES. JTonbon : MACMILLAN AND CO. 1878. [Tlie Right of Translation and Reproduction is Reserved.} LONDON : R. CLAY, SONS, AND TAYLOR, BREAD STREET HILL, E.C. TENTH THOUSAND. ■

Preface

. Nearly nine years ago, I was invited, by the Managers of the London Institution, to take part in a series of courses of Educational Lectures ; which were intended to initiate young people in the elements of Physical Science. My course was to be the first of the series j and I made use of the opportunity, thus afforded me, to put into practical shape the ideas, which I had long entertained and advocated, respecting the proper method of approach ing the study of Nature. It appeared to me to be plainly dictated by common sense, that the teacher, who wishes to lead his pupil to form a cle^r mental picture of the order which pervades the multiform and endlessly shifting phenomena of nature, should commence with the. familiar facts of the scholar's daily experience ; and that, from the firm ground of such experience, he should lead the beginner, step by step, to remoter objects and to the less readily comprehensible relations of things. In short, that the knowledge of the child should, of set purpose, be made to grow, in the same $t

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. VI manner as that of the human race has spontaneously grown. I conceived that a vast amount of knowledge respecting natural phenomena and their interdependence, and even some practical experience of scientific method, could be Conveyed, with all the precision of statement, which is what distinguishes science from common information ; and, yet, without overstepping the comprehension of learners who possessed no further share of preliminary educational dis cipline, than that which falls to the lot of the boys and girls who pass through an ordinary primary school. And I thought, that, if my plan could be properly carried out, it would not only yield results of value in themselves, but would facilitate the subsequent entrance of the learners into the portals of the special sciences. I undertook, therefore, to deliver twelve lectures, not on any particular branch of natural knowledge, but on natural phenomena in general ; and I borrowed the title of " Physio graphy," which had already been long applied, in a different sense, to a department of mineralogy, for my subject ; inasmuch as I wished to draw a clear line of demarcation, both as to matter and method, between it and what is commonly understood by " Physical Geography."

Many highly valuable compendia of Physical Geography, for the use of scientific students of that subject, are extant ; but, in my judgment, most of the elementary works I have seen, begin at the wrong end, and too often terminate in an omnium gatherum of scraps of all sorts of undigested and unconnected information; thereby entirely destroying the educational value of that study which Kant justly termed the "propædeutic of natural knowledge."

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. VII I do not think that a description of the earth, which commences, by telling a child that it is an oblate spheroid, moving round the sun in an elliptical orbit; and ends, without giving him the slightest hint towards under standing the ordnance map of his own county ; or any suggestion as to the meaning of the phenomena offered by the brook which runs through his village, or the gravel pit whence the roads are mended ; is calculated either to interest or to instruct. And the attempt to convey scientific con ceptions, without the appeal to observation, which can alone give such conceptions firmness and reality, appears to me to be in direct antagonism to the fundamental principles of scientific education. " Physiography " has very little to do with this sort of " Physical Geography." My hearers were not troubled with much about latitudes and longitudes ; the heights of moun tains, depths of seas ; or the geographical distribution of kangaroos and Compositæ.

Neglecting such pieces of information — of the importance of which, in their proper places, I entertain no doubt — I endeavoured to give them, in very broad, but, I hope, accurate, outlines, a view of the " place in nature " of a particular district of England, the basin of the Thames ; and, to leave upon their minds the impression, that the muddy waters of our metropolitan river ; the hills between which it flows ; the breezes which blow over it ; are not isolated phenomena, to be taken as understood because they are familiar. On the contrary, I endeavoured to show that the application of the plainest and simplest processes of reasoning to any one of these phenomena, suffices to show, lying behind it, a cause, which again suggests another; until, step by step, the conviction dawns upon the learner that, to attain to even an elementary conception

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. VIII of what goes on in his parish, he must know something about the universe ; that the pebble he kicks aside would not be what it is and where it is, unless a particular chapter of the earth's history, finished untold ages ago, had been exactly what it was. It was necessary to illustrate my method by a concrete case; and, as a Londoner addressing Londoners, I selected the Thames, and its basin, for my text. But any intelligent teacher will have no difficulty in making use of the river and river basin of the district, in which his own school is situated, for the same purpose. The lectures on Physiography were delivered at the London Institution in 1869 ; and I repeated them, at South Kensington, in 1870. Verbatim reports were taken on the former occasion, as it was my intention to publish the course.

But I am sorry to say that, in this, as in other cases, I have found a great gulf fixed between intention to publish and its realization. Seeing a book through the press is a laborious and time wasting affair ; greatly aggravated, in cases such as the present, by the necessity of superintending the execution of maps and figures. And, as I never could muster up the courage, or find the time, to undertake the business, the manuscript remained untouched until last year. I then had the good fortune to be able to obtain the services of my friend Mr. Rudler, with whose extensive knowledge of various branches of physical science, I was well acquainted ; and, in whose conscientious accuracy, as an editor, I knew I could place implicit confidence. In preparing the substance of the lectures for the press,

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. IX Mr. Rudler has entirely fulfilled my expectations, and has made many valuable suggestions and additions. I have entirely re-written such parts of the work as I thought I could improve ; I have added to others ; and I have carefully revised the proofs of every chapter. I trust therefore that the book maybe useful to both learners and teachers ; but, I am most concerned, that the latter should find in it the ground-work of an introduction to the study of nature, on which their practical experience will enable them to erect a far better superstructure than that which I have been able to raise. T. H. H. London, November, 1877.

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TO THE SECOND EDITION. Several friends of mine have been good enough to read this work critically, and I have gladly availed myself of their suggestions to remove ambiguities of phraseology and errors of the press which had escaped my notice. One of the most important errata to which my attention has been thus called, respects the occurrence of an eruption of Mount Ararat (p. 191), which, though mentioned on very good authority, turns out to have been no eruption at all. The gravest mistake, however, is one which I have had the melancholy satisfaction of discovering for myself. At p. 84, the decimal points have got wrong in the course of the calculation of the weight of the air covering a square mile : whereby that weight is made to be ten times, and the weight of the contained carbonic acid gas a hundred times as great as it should be.

Happily, when the amounts given are rectified, the quantity of carbonic acid in the air is still amply sufficient for the purposes of the argument. T. H. H. London, February, 1878. CONTENTS.

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