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clear to us—in fact, they could not have and for Clerk Maxwell more fully to been clear to him; but he seems to have develop, its most important consequences. felt a conviction that if he only tried [The principle of the experiment was long enough, and sent all kinds of rays then illustrated by the aid of a mechaniof light in all possible directions across cal model.] electric and magnetic fields in all sorts This is the fundamental experiment on of media, he must ultimately hit upon which Clerk Maxwell's theory of light something. Well, this is very nearly is based; but of late years many fresh what he did. With a sublime patience facts and relations between electricity and perseverance which remind one of and light have been discovered, and at the way Kepler hunted down guess after the present time they are tumbling in in guess in a different field of research, great numbers. Faraday combined electricity, or mag It was found by Faraday that many netism, and light in all manner of ways, other transparent media besides heavy and at last he was rewarded with a re- glass would show the phenomenon if sult. And a most out-of-the-way result placed between the poles, only in a less it seemed. First, you have got to get a degree; and the very important observamost powerful magnet and very strongly tion that air itself exhibits the same excite it; then you have to pierce its two phenomenon, though to an exceedingly poles with holes, in order that a beam of small extent, has just been made by light may travel from one to the other Kundt Röntgen in Germany. along the lines of force; then, as ordina Dr. Kerr, of Glasgow, has extended the ry light is no good, you must get a beam result to opaque bodies, and has shown of plane polarized light and send it be- that if light be passed through magnettween the poles. But still no result is ized iron its plane is rotated. The film obtained until, finally, you interpose a of iron must be exceedingly thin, bepiece of a rare and out-of-the-way mate- cause of its opacity, and hence, though rial which Faraday bad himself discover the intrinsic rotating power of iron is ed and made, a kind of glass which con- undoubtedly very great, the observed tains borate of lead, and which is very rotation is exceedingly small and diffiheavy, or dense, and which must be per- cult to observe; and it is only by very fectly annealed.
remarkable patience and care and ingeAnd now, when all these arrangements nuity that Dr. Kerr has obtained his reare completed, what is seen is simply sult. Mr. Fitzgerald, of Dublin, has exthis, that if an analyzer is arranged to amined the question mathematically, and stop the light and make the field quite has shown that Maxwell's theory would dark before the magnet is excited, then- have enabled Dr. Kerr's result to be predirectly the battery is connected and the dicted. magnet called into action - a faint and Another requirement of the theory barely perceptible brightening of the is, that bodies which are transparent to field occurs; which will disappear if the light must be insulators or non-conductanalyzer be slightly rotated. [The ex- ors of electricity, and that conductors of periment was then shown.] Now, no electricity are necessarily opaque to wonder that no one understood this re light. Simple observation amply consult. Faraday himself did not under- firms this; metals are the best conductstand it at all; he seems to have thought ors, and are the most opaque bodies that the magnetic lines of force were known. Insulators, such as glass and rendered luminous, or that the light was crystals, are transparent whenever they magnetized-in fact, he was in a fog, are sufficiently homogeneous, and the and had no idea of its real significance. very remarkable researches of Prof. Nor had any one. Continental philoso- Graham Bell in the last few months phers experienced some difficulty and have shown that even ebonite, one of the several failures before they were able to most opaque insulators to ordinary visrepeat the experiment. It was, in fact, ion, is certainly transparent to some discovered too soon, and before the sci- kinds of radiation, and transparent to no entific world was ready to receive it, and small degree. it was reserved for Sir William Thom [The reason why transparent bodies son briefly, but very clearly, to point out, must insulate, and why conductors must
be opaque, was here illustrated by me- than when it was in the dark.
The light chanical models.]
of a candle is sufficient, and instantaneA further consequence of the theory ously brings down the resistance to someis that the velocity of light in a trans- thing like one-fifth of its original value. parent medium will be affected by its I could show you these effects, but electrical strain constant; in other words, there is not much to see; it is an intensethat its refractive index will bear some ly interesting phenomenon, but its exterclose but not yet quite ascertained rela- nal manifestation is not striking-any tion to its specific inductive capacity. more than Faraday's heavy glass experiExperiment bas partially confirmed this, ment was. but the confirmation is as yet very in This is the phenomenon which, as you complete. But there are a number know, has been utilized by Prof. Graham of results not predicted by theory, and Bell in that most ingenious and striking whose connection with the theory is invention, the photophone. By the not clearly made out. We have the kindness of Prof. Silvanus Thompson I fact that light falling on the plati. have a few slides to show the principle num electrode of a voltameter generates of the invention, and Mr. Shelford Bida currert, first observed, I think, by Sir well has been good enough to lend me his W. R. Grove-at any rate it is men- home-made photophone, which answers tioned in his “ Correlation of Forces” exceedingly well for short distances. extended by Becquerel and Robert Sa I have now trespassed long enough bine to other substances, and now being upon your patience, but I must just alextended to fluorescent and other bodies lude to what may very likely be the by Prof. Minchin. And finally—for I next striking popular discovery, and that must be brief-we have the remarkable is the transmission of light by electriciaction of light on selenium. This fact ty; I mean the transmission of such was discovered accidentally by an assist things as views and pictures by means ant in the laboratory of Mr. Willoughby of the electric wire. It has not yet Smith, who noticed that a piece of sele- been done, but it seems already theoretinium conducted electricity very much cally possible, and it may very soon be better when light was falling upon it practically possible.
SCIENCE TEACHING IN THE PUBLIC SCHOOLS.
From the Proceedings of the American Association for the Advancement of Science.* REPORT OF COMMITTEE ON SCIENCE to a consideration of the subject. It was
TEACHING IN THE Public Schools: probably expected that we would furnish
The Committee appointed at the Sar- a digest of information from many quaratoga meeting of the American Associa- ters, as to what sciences are taught in tion on Science Teaching in the Public the public schools, with what facilities, Schools, respectfully submit the prelimi. and to what extent; accompanied by such nary Report.
recommendations regarding the increase The repeated appointment by this of scientific studies as the results might body, in successive years, of committees suggest. But our course has not proved to look into the scientific education of to be so clear. We have been arrested the public schools, must be taken as at the outset by a question of the quality showing that such an inquiry is regarded of the science teaching in these schools as both legitimate and important. Yet which demands the first consideration. the duties of such a committee have not
There are certain radical deficiencies in been defined by the Association, nor have
current science teaching, the nature and any of our predecessors opened the way extent of which must be understood before
any measures of practical improvement in the Public Schools. The committee consisted of here confine ourselves to this preliminary
* The report of the Committee on Science Teaching can be intelligently taken up. We shall E. L. Youmans, A. R. Grote, J. W. Powell, N. S. Sha
er and J. S. Newbery.
The investigations has interest from of widely diffusing the results of rethe immense extent, and rapidly increas. search; but they recognized that the ing influence, of the American public interests of science are so vast, as to schools. There are now nearly one hun- be only efficiently promoted by division dred and fifty thousand of these schools, of labor. Under the operation of this supported at an annual expense of proba principle it was made the distinctive purbly seventy or eighty million dollars. pose of the association to contribute to Maintained by state authority, they are the extension of original science by the firmly established in the respect and con- discovery of new scientific truth, leaving fidence of the community. Under the its dissemination to the schools, the press, influence of normal schools, teachers' and the various agencies of public eninstitutes, systematic superintendence, lightenment. Nor does your committee school boards, regulative legislation, and understand that it is now proposed to an extensive literature devoted specially depart from this policy; for the inquiry to education, they have become organ before us is really most pertinent to our ized into a system which is gradually special objects. It certainly cannot be a growing settled and unified in its meth- matter of indifference to this body, from ods. With unbounded means and un- its own point of view, how science is limited authority, these schools have dealt with in the great system of schools undertaken to form the mental habits of which has undertaken the task of mouldthe great mass of the youth of this coun- ing the youthful mind of the country. try. They prescribe the subjects of We aim to advance science by the prostudy, the modes of study, and the ex- motion of original investigation, which tent and duration of studies for all the depends upon men prepared for the work. pupils that come under their charge. Do the schools of the nation, by their The sphere of their operations is, more- modes of scientific study, favor or hinder over, steadily extending. They are this object? Do they foster the early everywhere encroaching upon the prov- mental tendencies that lead to original ince of higher education, everywhere thought; or do they thwart and repress trenching upon private schools and di- them? We have an undoubted concern minishing the interest in home educa- in this matter, and it is, moreover, strictly tion.
identical with that of the community at It
may be assumed that the time has large; for there can be no better test fully come when this system must be than this of the real character of a school measured by the standards of science, system. When we ask whether a mode and approved or condemned by the de- of teaching and a manner of study are gree of its conformity to what these calculated to awaken the spirit of instandards require. Science has become quiry, to cultivate the habit of investi. in modern times the great agency of hu- gation, and rouse independent thought, man amelioration, the triumphs of which our question goes to the root of all true are seen on every hand and felt in all education. experience. Grave subjects are brought All sciences are the products of a successively under its renovating and method of thinking, and it is that method reconstructive influence; and latest and which concerns us when we propose to most important among them is the sub- regard it as a means of mental cultivaject of education. Our inquiry now is, tion. Science is an outgrowth of comhow far the public-school system has mon knowledge, and the scientific method availed itself of the valuable aid that is but a development of the ordinary science offers in the proper cultivation of processes of thought that are employed the minds of the young.
by everybody. The common knowledge The interest and necessity of such an of people is imperfect because their obinvestigation will hardly be denied; but servations are vague and loose, their reathere may be a query as to its relevancy -soning hasty and careless, their minds to the appropriate work of this society. warped by prejudice and deadened by The making of science popular was not credulity, and because they find it easier among the objects for which our asso- to invent fanciful explanations of things ciation was formed. Not that its found than to discover the real ones. For thousers were unmindful of the importance ands of years the knowledge of nature
was rude and stationary because the said: “I will thank any person to show habits of thought were so defective. why it is expedient and beneficial in the But with a growing desire to understand community to make public provision for how the world around is constituted, teaching the elements of learning, and men improved their processes of think- not expedient or beneficial to make simiing. They began, and were compelled lar provision to aid the learner's progress to begin, by questioning accepted 'facts, toward the mastery of the most difficult and doubting current theories. The first branches of science and the choicest restep was one of self-assertion, implying finements of literature.” Under the inthat degree of mental independence fluence of such considerations the rudiwhich led men to think for themselves. mentary studies rapidly developed into They learned to make their own observ- sources of study embracing a variety of ations and to trust them against au- subjects. This led to the systematizing thority. It was found, as a first and in- of instruction and the grading of schools, dispensable condition of gaining clear so that in nearly all the towns of the ideas, that the mind must be occupied United States the public schools have directly with the subject to be investi- been divided into primaries for the gated. In this way scientific inquiry at younger pupils and the grammar schools length grew into a method of forming for older pupils; while within twentyjudgments which was characterized by five years a third grade has arisen known the most vigilant and disciplined precau- as the high schools for the most advaneed tions against error. Of the mental pro- students. In each division there are subcesses involved in research it is unneces- grades, and wherever improvements in sary here to speak; we are only con- public-school education are attempted, cerned to know that the scientific method the principle of gradation is fundamental. is simply a systematic exercise in truth. So essential is it considered, that no aid seeking, and is the only mode of using is granted from the Peabody fund exthe human mind when it is desired to at-cept to graded schools. As regards the tain the most accurate and perfect form plan of studies adopted there was no of knowledge. The whole body of mod- guiding principle. All sorts of subjects, ern scientific truth, disclosing the order and these for all sorts of reasons were of nature and guiding the development taken up, and among them the sciences of civilization, must be taken as an attest- which are now regular parts of public ation of the validity of the scientific school duty. Classes are found in physmethod of thought by which these re- ics, chemistry, mineralogy, geology, sults have been established. We here physiology, botany and zoology.
There get rid of all cramping limitations. The are text-books upon all these branches, scientific method is applicable to all sub graded to the varying capacities of learnjects whatever that involve constancy of ers. Teachers prepare in them, and in relations, causes and effects, and conform many cases apparatus is provided, and to the operation of law. It is applicable there are lectures with experiments, spewherever evidence is to be weighed, error specimens, maps and charts for illustragot rid of, facts determined, and princi- tions. ples established. Our public schools, The old ideal of a school is a place unhappily, make but little use of this where knowledge is got from books by method in the work of mental cultiva- the help of teachers, and our public tion, and we shall find some explanation school system grew up in conformity of this by referring to the way they grew with this ideal. The early effect of up.
grading was to fix and consolidate imThe American public school system origi- perfect methods. The sciences were asnated in the theory that the State owes similated to the old practice, and the to every child the rudiments of a common science teaching falls short at just the education, or an elementary knowledge of points where it was inevitable that it reading, writing and arithmetic, as im- should fall short. The methods of school plements of after mental improvement. | teaching, and the habits of the teachers, But it was early found difficult to sepa- had grown rigid under the regime of rate the primary use of tools from the book-studies. As a consequence the sciacquisition of knowledge. Mr. Everett lence teaching in the public schools is
generally carried on by instruction. fessed purpose of cultivating the powers Through books and teachers the pupil is of observation in childhood. It is claimed filled up with information in regard to that this is a beginning in science ; and, science. Its facts and principles are ex- as it brings the mind into action upon plained as far as possible, and then left things, is a corrective of the inordinate in the memory with his other school ac- study of words. But object teaching has quisitions. He learns the sciences much not yielded what was expected of it; as he learns geography and history, Only and is in no true sense a first step in sciin a few exceptional schools is he put to ence. Nothing is gained educationally any direct mental work upon the sub- by barely having an object in hand ject-matter of science, or taught to think when it is talked about. Myriads of for himself.
objects are present to the senses of peoAs thus treated the sciences have but ple but no insight follows. The observ. value in education. They fall below ing faculties must be tasked if they are other studies as means of mental culti- to be trained. The pupil is not to have vation. Arithmetic arouses mental re- the properties of objects pointed out, action. The rational study of language, but he is to find them out. Science will by analytical and constructive tasks and do its work of educating the observing the mastery of principles, strengthens faculties only as they are quickened and the mental processes; but the sciences sharpened by exercise in discrimination. are not employed to train the faculties The scientific aim is to replace vague conin the various ways to which they are fused impressions by clear and accurate severally adapted. They are not made ideas. Skill in the detection of nice disthe means of cultivating the observing tinctions is only gained by prolonged powers, stimulating inquiry, exercising and careful practice. Object lessons afthe judgment in weighing evidence, nor ford no such cultivation. We do not say of forming original and independent they are useless, but they are not the A habits of thought. The pupil does not B C of science, and do not, as a matter know the subjects he professes to study of fact, open the way to the proper study by actual acquaintance with the facts, of the special sciences. This is their test and he therefore becomes a mere passive and their condemnation. When the accumulator of second-hand statements. primary pupils have gone over their preBut it is the first requirement of the sci- scribed course of object lessons, and are entific method, alike in education and in passed on to a higher grade, strange to research, that the mind shall exercise its say the “ objects ” are suddenly dropped activity directly upon the subject matter as if the objective method had been exof study. Otherwise scientific knowledge hausted. In the technical phrase peris an illusion and a cheat. As science is ceptive education is to be replaced by commonly pursued in book descriptions conceptive education. Instruction in ele . the learners cannot even identify the mentary science is now to be carried on things they read about. As remarked by what is known as oral teaching. This by Agassiz, “the pupil studies Nature in method as extensively practised in the the school-room, and when he goes out grammar grades of the public schools is of doors he cannot find her.” This mode everywhere growing in favor, and we are of teaching science, which is by no once more told that it is a successful means confined to the public schools, revolt against book studies. It is chiefly has been condemned in the most unspar- applicable to the sciences and its cardiing manner by all - eminent scientific nal idea is instruction without a text
deception,” a “fraud,” an book. This looks fair but it is delusive. "outrage upon the minds of the young,” The method does not remove the book an imposture in education."
that the pupil may come at the phenomNor has this criticism of bad practices ena, but it removes the book that the been without its effect. We are met by teacher may take its place. Oral teachthe statement that much has been done in ing is class instruction, in which informathe public schools to escape the evils of tion is imparted in a familiar manner mere book science. The method of ob with the view of awakening the interest ject lessons has been extensively intro- of the class. But so far as real science duced into primary schools with the pro. is concerned it is doubtful if this method
men as a