number of investigators. Superintendent W. H. Thomas has been designated acting director of the laboratory for the season. Dr. George T. Moore, of the Missouri Botanical Garden, assisted by F. B. Dieuaide, will conduct experiments on the production and utilization of algin. Professor Edwin Linton, of Washington and Jefferson College, will continue investigations of the parasites of fishes and the food of flounders and other fishes.

The Beaufort laboratory having been turned over to the Navy Department, no work will be done there this summer.

THE AMERICAN INSTITUTE OF MINING ENGINEERS

In an effort to increase the scope of their war service, the American Institute of Mining Engineers will meet in Colorado during the week of September 2, to take up vital problems of immediate importance. Mining engineers from every section of the country will attend. During the meeting, trips are to be made from Colorado Springs to the Cripple Creek district, Pueblo, the Leadville district and Boulder. The week's session will open in Denver on the second of September, and will that evening move to Colorado Springs, which will be the principal headquarters for the duration of the meeting.

This is the first meeting of the entire institute in Colorado since 1896, and an appropriate entertainment program is being planned by the several hundred Colorado members. One of the special features of the entertainment will be an auto drive to the top of Pikes Peak. The sections of Colorado to be visited are rich in many war minerals of importance including ferro alloys, radium, molybdenite ores and pyrites.

Those who are directing the plans for the Colorado meeting are as follows: Committee in charge, Spencer Penrose, chairman, A. E. Carlton, chairman finance committee, George M. Taylor, vice-chairman, J. Dawson Hawkins, secretary. Denver Committees: (Arrangement) Dave G. Miller, Frank Bulkley, Geo. E. Collins; (Entertainment) F. H. Bostwick, F. E. Shepard, Howland Bancroft, B. P.

Morse, J. G. Perry; (Finance) T. B. Stearns, Richard A. Parker, T. B. Burbridge.

THIRD SUMMER MEETING OF THE MATHEMATICAL ASSOCIATION OF AMERICA IT is announced in the American Mathematical Monthly that the third summer meeting of the Association will be held by invitation of Dartmouth College at Hanover, New Hampshire, on Friday and Saturday, September 6-7, 1918, in conjunction with, and following, the summer meeting of the American Mathematical Society. A joint dinner will be arranged for Thursday evening, September 5, and at a joint session on Friday morning the subject of the mathematics of warfare is to be treated by men now actively engaged in government service.

During the sessions of the association on Friday and Saturday, Professor Florian Cajori, of the University of California, will deliver his address, as retiring president, on "Plans for a History of Mathematics in the Nineteenth Century"; Professor W. F. Osgood, of Harvard University, will speak "On the Mathematical Formulation of Physical Concepts and Laws as treated in the Calculus"; and Professor F. L. Kennedy, of Harvard University, will give a paper on Some Experiments in the Teaching of Descriptive Geometry," the discussion being led by Dean O. E. Randall, of Brown University. Other features of the association's program will be announced later.

For a session on Friday members are invited to submit papers on topics of their own choosing. Abstracts of such papers in a form suitable for publication in the Secretary's report of the meeting should be sent to Professor R. C. Archibald, Brown University, chairman of the program committee, not later than August first, in order to be approved by the committee in time for publication in the printed program; authors will please state the time necessary for reading their papers. No other announcement will be made until the program is mailed to members about the middle of August.

The committee on arrangements, Professor J. W. Young, chairman, announces that Dartmouth College will open one of its dormitories for the accommodation of attending members.

SCIENTIFIC NOTES AND NEWS SIR WILLIAM CROOKES, O.M., celebrated his eighty-sixth birthday on June 17.

MR. HORACE LAMB, F.R.S., professor of mathematics in the University of Manchester, has been appointed Halley lecturer at Oxford University for next year.

DR. WILLIAM S. THAYER, of the Johns Hopkins University, now a colonel in the National Army, has been made a foreign member of the French Academy of Medicine.

A SECTION of Anthropology in the Division of Medical Records in the Office of the Surgeon General, was created on July 23, 1918. Major Chas. B. Davenport, Sanitary Corps, N. A., has been designated as the officer in charge. The functions of this section are to be: To secure the highest quality of the measurement of recruits and of identification rec

ords as done by the Surgeon General's Office for the purposes of the War Department; to assist, as called upon, in the analysis and synthesis of the statistics compiled from medical records; to care for and help analyze physical examination records; to care for and classify identification records, and to assist the War Department in all questions about racial dimensions and differences.

PROFESSOR E. V. HUNTINGTON, president of the Mathematical Association of America, has taken leave of absence from Harvard University and with the rank of major in the national army is assigned to statistical study under the chief of staff with residence in Washington.

PROFESSOR A. D. COLE, professor of physics at Ohio State University, is in Washington

for the summer, engaged in research work in the Bureau of Standards.

MR. W. L. CURRIE, of Glasgow, has been elected president of the Pharmaceutical Society of Great Britain.

THE Association of Military Surgeons of the United States will hold its annual meeting for 1918 at Camp Greenleaf, Fort Oglethorpe, Ga., on October 13 and 15, under the presidency of Medical Director George A. Lung, of the U. S. Navy.

By request of the Secretary of War and the Secretary of the Navy the National Research Council has formed a committee on explosives investigations composed of Lieutenant Colonel W. C. Spraunce, Jr., Ordnance, National Army, nominated by the Chief of Ordnance of the Army; Lieutenant Commander T. S. Wilkinson, United States Navy, nominated by the Chief of Ordnance, United States Navy, and Mr. L. L. Summers, representing the War Industries Board, with Dr. Charles E. Munroe, dean of the faculty of graduate studies of the George Washington University, as chairman. The functions of the committee as officially defined are: (1) To survey the investigations on explosives now under way and to keep closely in touch with their subsequent progress. (2) To gather and communicate to the proper military and naval authorities all information available in regard to such investigations. (3) To bring to the attention of the proper military and naval authorities proposals for supplementary investigations relating to explosives, and to arrange for the prosecution of such investigations by the civilian bureaus of the government, by industrial companies and by universities and endowed research institutions. The office of the committee is in the building of the National Research Council at 1023 Sixteenth Street, Washington, D. C.

DRS. C. E. FERREE and G. Rand, of Bryn Mawr College, presented a paper at the fiftyfourth Annual Convention of the American Ophthalmological Society on July 10 on "The Inertia of Adjustment of the Eye for Clear Seeing at Different Distances." A method and apparatus were described for testing for

fitness for aviation and other vocations for which speed and accuracy of adjustment of the eye for clear seeing at different distances are a prerequisite.

IN accordance with plans for cooperation of the Bureau of Chemistry and the Bureau of Fisheries on problems of preparation and preservation of fishery products for food, Dr. F. C. Weber, of the Bureau of Chemistry, and Drs. G. G. Scott and W. W. Browne, of the College of the City of New York, temporary assistants of the Bureau of Fisheries,

have begun work for the summer at Perkins Laboratory, Gloucester, Mass., where facilities. and cooperation are afforded by the GortonPew Fisheries Co.

UNIVERSITY AND EDUCATIONAL
NEWS

THE University of Chicago has received from Mr. La Verne Noyes a gift of $2,500,000, to be used in the education of soldiers and sailors and their descendents after the war. In addition the fund provides for the perpetuation of instruction in American history and the public duties of citizenship.

COLUMBIA UNIVERSITY is a beneficiary under the will of Major Eugene Wilson Caldwell, of the United States Medical Reserve Corps, from two trust funds upon the death of life tenants to support a foundation for general educational work. Dr. Caldwell died in Roosevelt Hospital from burns received while experimenting with X-rays. His estate was valued at more than $150,000.

THE Kansas City Veterinary College, after an existence of twenty-seven years, during which it has graduated nearly 1,700 men, has decided to abandon the field of veterinary education. It has transferred to the Kansas State Agricultural College its records and good will, and made arrangements with that institution to take over its students as far as possible and agreeable to them.

THE Department of Chemistry of the State College of Washington, Pullman, Washington, announces the establishment of a fellowship,

to be devoted to research on the extension of the chemical uses of magnesite, paying $600 a

year.

DR. C. W. MOCAMPBELL, for eight years a member of the department of animal husbandry of the Kansas State Agricultural College, is the new head of the department, succeeding Professor W. A. Cochel, who has resigned.

PROFESSOR J. H. RANSOM, after eighteen years in Purdue University, has accepted the professorship of chemistry and director of the

chemical laboratories in Vanderbilt University, Nashville, Tenn.

W. V. LOVITT, Ph.D., Chicago, of the mathematical department of Purdue University, has been appointed associate professor of mathematics in Colorado College.

THE electors to the Harkness scholarship in geology in Cambridge University have recommended that the scholarship for women for 1918 be awarded to Majorie E. J. Chandler, Newnham College.

SIR CHARLES PARSONS has accepted the office of president of the Polytechnic School of Engineering, London, in succession to the late Mr. Charles Hawksley.

DR. MAUD KINNAMAN, of Washington, N. J., has been made head of the new medical college at Vellore, India.

DISCUSSION AND CORRESPONDENCE

THE FUNDAMENTALS OF DYNAMICS Most discussions of elementary mechanics refer to variations in point of view and especially to variations of emphasis which are all equally logical and all fully understood by careful students of the subject. Therefore, discussions of elementary mechanics usually say a great deal to "put over a mere grain of edification, and Professor E. V. Huntington's recent discussions of elementary mechanics in SCIENCE and in the American Mathematical Monthly is no exception to the general rule. From the most favorable point of view, Professor Huntington's discussion is much ado about nothing; but from our point of view it

is much worse than that. If we were not convinced that Professor Huntington is definitely mistaken in several important matters we would not, for a third time, take part in the discussion.

1. Professor Huntington urges the use of the term standard weight, the weight of a body in London in "pounds," instead of mass. Now what we call the mass of a body is independent of time and place, it is an invariant2 relation between the given body and the standard kilogram (a piece of metal), and extraneous and confusing ideas would be involved in the term standard weight, because this term implies location and a relationship between the given body and the earth. How awkward it would be, for example, to be obliged always to speak of the distance d between two points (x, y, z) and (x', y', z') as [(x−x')2+ (y-y')2+(zz')]. This function is an invariant, and the most useful name or symbol for it is a name or symbol which carries no redundant suggestions as to particular axes of reference, and this would be true even if we had always to make use of particular axes of reference in the measurement of d. The word mass is widely used by physicists and chemists for an idea which is independent of time and place and which does not involve any relationship with the earth (this is true even though mass be determined by weighing), and it is simply out of the question to use for this idea the term standard weight with its redundant and misleading suggestions.

2. To be unfriendly to the term mass and to prefer the term standard weight is of course a small matter; but Professor Huntington seems to go much deeper than mere terminology. He insists, for example, on the equation F/F" = a/a' as THE fundamental equation of dynamics, although several correspondents in SCIENCE have called his attention to the fact that acceleration not only varies from force to force for a given body but also from body to body

1 The "pound'' here means the pull of the earth on a one-pound body in London.

2 No consideration is here given to variations of mass as recognized in the recent developments of the principle of relativity.

for a given force. Both of these fundamental modes of variation must be formulated as fundamental equations of dynamics. Professor Huntington states that the variation-frombody-to-body-for-a-given-force is logically derivable from the variation-from-force-to-forcefor-a-given-body, and the object of the following discussion is to make it clearly evident that Professor Huntington's statement is not true.

Given three bodies A, B, and C, and three identifiable forces a, b and c. Let the acceleration of each body due to each force be observed, the results being shown in the accompanying table. Let us suppose that the table has been

extended so as to include a great many different forces and a great many different bodies, then a careful inspection of the table would lead to the following generalizations:

(a) If one force produces twice as much acceleration as another force when acting on a given body, then the one force produces twice as much acceleration as the other force when acting on any body whatever.

(b) If one body is accelerated twice as much as another body under the action of a given force, then the one body is accelerated twice as much as the other body under the action of any force whatever.

The experimental fact (a) makes it convenient to define the ratio of two forces as the ratio of the accelerations they produce when acting on a given body, because this ratio is the same for all bodies. That is

where a is the acceleration of body No. 1 and a' is the acceleration of body No. 2, both produced by a given force, and m and m' are the masses of the respective bodies.

We prefer to define mass quantitatively in terms of the operation of weighing by a balance scale and to look upon equation (2) as an experimental discovery; but in any case equations (1) and (2) are independent and they are the fundamental equations of dynamics. Equation (1) applies to a given body, and pure logic would not even know of the existence of another body, so that equation (2), inasmuch as it refers to at least two bodies, can not be a logical consequence of equation (1). It is surprising to us to have Professor Huntington refer to the above table of observed accelerations in support of his statement that equation (2) is a logical or mathematical consequence of equation (1). Of course we have not observed these accelerations, but in the last analysis they are dependent on observation and upon nothing else.

3. Professor Huntington's statements as to systematic units are very much like most current text-book statements touching this matter. "Fundamental units may be chosen at pleasure "-so all of our talking physicists say, mentioning only the evident condition that material standards thereof must be carefully preserved. Working physicists, however, know that the fundamental quantities must be susceptible of very accurate measurement under all sorts of conditions and in all kinds of relations because the definition of a derived unit can not be realized with greater accuracy than the fundamental quantities can be measured. 4 SCIENCE, March 3, 1916, page 315.

Think of the years of confusion in electrical measurements when the theoretical ohm could not be produced with greater accuracy than, say, one per cent., but when almost anybody could make resistance measurements to, say, a hundredth of one per cent! When we recall that old nightmare we are inclined to smile at the childish pleasure with which many teachers talk about choosing fundamental units. Indeed, one fundamental unit would be enough if certain measurements, which would then be fundamental, could be made with sufficient accuracy. This important condition of accurate realization of derived units makes it undesirable to use the pull of the earth on a one-pound body in London (or on a one-gram body) as a fundamental unit in any universally practicable system. As a matter of widest practise the use of the unit of force as a fundamental unit is out of the question. We admit, however, and here we differ from some of our colleagues in physics, that the C.G.S. system (or the F.P.S. system) is less convenient than the foot-slug-second system in some fields of engineering."

4. It is extremely amusing to read Professor Huntington's naïve suggestion that a unit of force might be preserved in the form of a standard spring. This is laughable for two reasons, namely, (a) because the pull of the earth on a one-pound body in London is perhaps as invariable as its mass so that no standard spring is needed to preserve a unit of force, and (b) because, as every working physicist knows, the most carefully "aged" springs grow very perceptibly softer in time. Tempered steel and phosphor bronze and fused quartz are unstable substances.

5. We are at a loss to understand the significance of Professor Huntington's efforts to establish order in the fundamental view points of mechanics except on the assumption that he has felt, somewhat vaguely, the central fallacy,

5 We publish in a current number of the Bulletin of the Society for the Promotion of Engineering Education a brief and simple discussion of this subject, a discussion which we think may show the way to a general agreement among writers on mechanics.