cussed by Drs. Heitzmann, Wilder, Dwight and Lamb.

few of your readers are aware, I printed privately, last summer, a brief circular

time of doing so I was at an out-of-the-way spot in the country, where it was impossible to exchange inspirations, except by post, with friends whose interest in the scheme might have been counted upon; but upon

11. The correlation between specific diversity and individual variability, as illustrated by the eye muscle nerves of the Amphibia.' Professor C. Judson Herrick.

The discussion on papers 8 to 11, inclusive, was then opened by Dr. Baker, and continued by Dr. Shepherd (who illustrated his remarks with specimens), Dr. Wilder, Dr. Lamb (who also showed a specimen), Dr. Huntington, and concluded by Dr. Dwight. Dr. Wilder exhibited a brainless frog and made remarks thereon.

On motion, the thanks of the Association were tendered to the College, and particularly to Dr. Huntington, for their hospitality.

The following members were present at some time during the session: Allen, Baker, Bevan, Bosher, Dwight, Ferris, Gerrish, Hamann, Heitzmann, C. J. Herrick, Huntington, Lamb, Moody, Shepherd, Spitzka, Weisse, Wilder. Total, 17.

CORRESPONDENCE.

A CARD CATALOGUE OF SCIENTIFIC

LITERATURE.

EDITOR OF SCIENCE-Dear Sir: Your invitation to open in the columns of SCIENCE a discussion of the projected Catalogue of Scientific Literature to be prepared by international coöperation, the claims of which were presented in your issue of February 15, affords me a welcome opportunity to fall publicly into line with a great movement that I believe destined to prove of the highest importance to scholarship. As a

became so convinced that the learned world was in sore straits in this matter, and that the way out was clear, that I felt sure I should presently discover that other restive spirits were beginning to agitate in the same direction. Little did I expect, however, to meet with so conspicuous and agreeable a confirmation of my premonition as came to me several weeks after the issuance of my circular (though dated before it), in the printed report of the Harvard committee, which has now appeared in SCIENCE. (The original communication of the Royal Society I have seen for the first time, through your editorial courtesy, in the proof sheets of SCIENCE.)

Although several of the suggestions contained in my own little circular were promptly outgrown by me, it may appear not inappropriate, on the principle of comparing small things with great, to reproduce here the contents of this highly aspiring but wholly unpretentious little document:

UNIFORM CARD MEMORANDUM INDEX.

The accompanying slip (size 24x31⁄2 inches, 5.7 x 8.9 centimetres), designed to be cut out and filed alphabetically in the manner of a card catalogue, is printed as a tentative specimen of a projected Uniform Card Memorandum Index, and is herewith privately submitted to representatives of a few of the leading universities, learned societies and publication agencies, with a view to securing influential approval of the general plan, together with useful suggestions and criticisms as to its practical application. It is proposed that all the universities, learned societies and high-class periodicals of the world should cooperate (from January, 1895) in the production of such a uniform memorandum index, by publishing, as a supplement (or appendix, or both) to every number of their original publications, a brief slipdigest of the contents of each article or even of important portions of each article, as may appear to be warranted. These supplements could be easily prepared (the digests being furnished in all or in most cases by the authors themselves), would be inexpensive both in their original form of publication and as separate slips, and would incalculably facilitate both the distribution and the classification for instant reference of all the newest results of discovery and research. Those interested in such a project are earnestly requested to communicate on the subject, before September 15, with the undersigned.

The specimen slip read as follows:

KINETO-PHONOGRAPH. PHONO-KINETOGRAPH. PHONO-KINETOSCOPE. Edison, Thomas A., Invention of the Kineto-phonograph. Century Magazine, June, '94, p. 206. "In the year 1887 the idea occurred to me that it was possible to devise an instrument which should do for the eye what the phonograph does for the ear, and that, by a combination of the two, all motion and sound could be recorded and reproduced simultaneously. This idea, the germ of which came from the little toy called the Zoetrope, and the work of Muybridge, Marié and others, has now been accomplished, so that every change of facial expression can be recorded and reproduced life size. The Kinetoscope is only a small model illustrating the present stage of progress, but with each succeeding month new possibilities are brought into view, etc., etc."

The above circular, though sent to but comparatively few persons, called forth a gratifying number of adherences' and of valuable suggestions. In particular, the president of one of the American universities famous for activity in research and in the promulgation of knowledge undertook to have furnished, with the official imprimatur, summaries of the contents of all the publications of his university.

The necessity of entrusting the organization of the enterprise to a great central bureau that would command universal confidence early became manifest, and an informal communication on the subject was addressed to one of the officers of the Smithsonian Institution at Washington, who wrote in response: "I heartily favor the idea. When you have the matter in shape to make a formal proposition I shall have much pleasure in recommending it to the Secretary."

Meanwhile, from correspondence and conference with numerous scholars, various points involved in the success of the enterprise have grown in distinctness. The problem of utilizing more effectively the ever-increasing mass of accumulated, scattered and current contributions to knowledge can no longer be shirked. The time is ripe for instituting widely concerted action for recovering mastery of the situation. The various efforts hitherto directed to this end have done great service; but they have been devised almost exclusively to meet the requirements of reference and circulating

libraries in their relations to broad classes of readers, rather than to serve the immediate needs of the individual scholar engaged upon a learned specialty.

All productive scholars, it would seem, must have devised or adopted for their personal use some form of index rerum, some mode-systematic or unsystematic-of note making. It is safe to say that very many such scholars have adopted for this purpose the general idea of the alphabetical card index, the merits of which are at present almost universally recognized. The scholar of Anglo-Saxon race is fast becoming as wedded to, and as dependent upon, his reference slips as the German scholar has long been silently devoted to his Zettel or the French savant to his fiches. It now remains for the Anglo-Saxon, with his openness to new applications of old ideas and the proverbial genius of his race for practical devices, to bring the power of the printing-press, as well as of scholarly cooperation, to bear upon the problem of multiplying indefinitely the benefits of the private card index.

Just here I should like to emphasize a consideration that is unexpressed, though latent, in the masterly report of the Harvard committee. This is, that such a card catalogue as is there projected, if based upon a wise choice in the size of card adopted, would render it possible for every member of the rapidly recruiting army of those employing the card system for private notes to incorporate his own manuscript or type-written cards and the printed cards (pertaining to his own specialty) of the coöperative index into one homogeneous whole, ever-growing, ever abreast of the latest research. This consideration it was, with all the possibilities and problems of administration it opens up, that held the mind of the writer under a spell of fascination for almost a week of vacation leisure. For be it noted that the blessings of the proposed coöperative card

index are to flow directly into the lap of the individual scholar, seated at his own desk in his private sanctum, enabling him to discard (not inappropriate word) to the limbo of the great libraries everything that does not directly concern him, while filing within reach of his finger-tips absolutely everything (pardon the optimism of an enthusiast) that he may intimately desire.

How can so Utopian a consummation be most speedily attained?

Let universities and colleges, and all manner of learned institutions and societies, at once appoint committees similar to the Harvard committee (though of course not limited to the natural and physical sciences, since the project of the Royal Society will form only a portion of the great undertaking), to accomplish three preliminary objects:

1. To arouse an intelligent and earnest interest in the subject.

2. To induce the Smithsonian Institution to assume the American leadership of the movement.

3. To convince publishers-primarily the publishers to the respective institutions concerned-of the importance of printing, on slips of the standard size, No. 33, of the American Library Bureau (73x12 cm., 3x5 in. approximately), summaries of their current publications for distribution as publishers' announcements. This size of slip is already widely in use, both publicly and privately, and may well prove to be of the dimensions ultimately adopted by the authorities of the projected international index. A beginning of these publishers' announcements has already been made by Messrs. D. C. Heath & Co., at the personal request of the present writer, and has been favorably submitted to the attention of the Secretaries of the Royal Society by Professor Bowditch, chairman of the Harvard committee. Other leading American pub

SCIENTIFIC LITERATURE.

Electrical Engineering, for Electric Light Artisans and Students. By W. SLINGO and A. BROOKER. New and revised edition, London, 1895. Longmans. Price, $3.50. The object of this work is to cover general electrical engineering, and, taken as a whole, it is probably the most successful attempt yet made in this direction. The demand for a satisfactory general treatment of the applications of electricity is a very large and important one, and anything which supplies this demand is more than welcome. It is very doubtful whether any single work is ever likely to be published which will completely set forth the numerous and rapidly developing branches of electrical science and industry. Nothing short of an encyclopædia of many volumes could be expected to accomplish this result. A general discussion of the most important principles and uses of electricity, particu

larly if it is not attempted to cover all branches, is a far more practicable problem, as the success of this volume demonstrates.

A work of this kind, however, is somewhat limited in its scope, since it is not intelligible to the ordinary untechnical reader, and is not of much use to the professional electrical engineer, who requires a more thorough and detailed study of each subject than is possible in a general treatise. This work would therefore be suited to one who had a certain amount of technical knowledge but who was not a specialist in electricity, for example, a mining or mechanical engineer, or a young man who had received a certain amount of electrical education at a technical or trade school and who wanted to learn more by his own efforts. It would also be useful as a textbook wherever a general course in electrical engineering is given. But in the opinion of the reviewer, a general treatment running from one subject to another is not the best way to educate electrical engineers of the highest type. This requires a careful and special study of each branch, aided by lectures and laboratory work, and the text-books should be entirely devoted to one subject, or, in fact, several books, each devoted to a small part of any one branch, is often preferable.

The authors of this book have had considerable experience as teachers and also the advantage of correcting and extending the contents of the first edition, which appeared in 1890, with the result that the new edition is well arranged and expressed and in most cases is brought reasonably well up to date. The first six chapters are devoted to general principles, units and methods of measurement. The next six chapters contain a treatment of dynamos and motors which is very satisfactory, considering the limitation of space. Transformers, secondary batteries, arc and incandescent lamps, are also well explained; but the last chap

ter, on Installation equipment, fittings, etc.,' is very meagre and the least satisfactory portion of the book. In fact, the principal criticisms would be that each element or device is explained as a separate thing, and no methods for combining these into systems are given. Nevertheless, it is a fact that the general design and arrangement of electrical apparatus is fully as important as the merits of each particular element. For example, the laying-out of a central station, or even a small isolated plant, determines its success or failure fully as much as the quality of the individual dynamos, lamps, or other particular parts of the plant.

The various systems for transmitting and distributing electric power, which is probably the most important branch of electrical engineering, are barely touched upon. In short, we may say that electrical engineering in its broadest sense is not covered, and probably was not intended to be covered, by this work. by this work. The subjects of electro-chemistry and electro-metallurgy, which now appear to be on the eve of important development, are not discussed. Telegraph and telephone apparatus and methods are not even mentioned.

These omissions, which are doubtless intentional and probably necessary, indicate that a complete treatise on electricity and its applications is almost an impossibility.

A few mistakes are noted; for example, on page 17, the International Ohm, adopted at the Chicago Electric Congress of 1893, is defined in terms of a column of mercury 106.3 centimetres in length and one square millimetre in cross section, whereas, the statement actually adopted was 'a column of mercury at the temperature of melting ice, 14.4521 grammes in mass, of a constant cross-sectional area and of the length of 106.3 centimetres.' This was intended to be exactly equivalent to a cross-section of one square mm., but it was put in this form because mass is more easily and ac