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SCIENCE. 



[Vol. XII. No. 



respect could be well supplied at a cost of five or six thousand dol- 

 lars per annum, and that the future prospects of the mathematical 

 sciences in this land depend very largely on their cultivators being 

 able to command this annual sum for the purpose indicated." 



In two of the particulars just mentioned — the encouragement of 

 advanced studies and the publication of results — this foundation 

 has aimed to do its part. By precept and example, hundreds of 

 young men have been trained in the methods of exact science and 

 the habits of accurate investigators. Not a few of these students 

 have been called into the scientific service of the government ; 

 many are engaged in laboratories, scientific and technical ; more 

 are employed as teachers in training up other young men. The 

 university can point to no result of its efforts which is so gratifying, 

 and which so thoroughly repays the outlays of this foundation, as 

 the corps of graduates who have gone out to every part of the 

 country, prepared to contribute to the progress of knowledge, and 

 who are now rendering good service to science, literature, and edu- 

 cation. By encouraging the publication of journals ^and mono- 

 graphs, this foundation has endeavored to supply another of the 

 deficiencies referred to above. Five periodicals, devoted to mathe- 

 matics, chemistry, biology, philology, and history, have been aided 

 by the university chest ; and three others, devoted to archeology, 

 psychology, and modern languages, have been initiated on the per- 

 sonal responsibility of certain members of the academic staff. 



President Oilman then considered the higher aspects of the work 

 of the university, especially during the last session. 



The subject of mathematics has received a large amount of at- 

 tention in the years gone by, as every one knov/s who remembers 

 the seven years' leadership of Professor Sylvester, the special 

 courses given by Professor Cayley and Sir William Thomson, and 

 the continued instruction of the present staff of mathematicians. 

 Every one that has an appreciation of the nature of mathematical 

 thought, or of its relation to the advancement of science, must re- 

 joice that this has been so. Dr. Whewell once claimed that mathe- 

 matics and civilization go forward hand in hand ; and quite recently 

 Lord Rayleigh, in reply to some contrary assertions, has said that 

 although some mathematicians are unpractical, yet it is to mathe- 

 matics one must go to find the results of known causes under new 

 circumstances. 



It has always been a surprise to President Oilman that so few 

 Americans are interested in the new and advancing developments 

 ■of this science, and that so large a number of those who are giving 

 their lives to mathematical professorships prefer to walk in well- 

 trodden paths without attempting to follow the higher flights of the 

 leaders. The number of mathematical students at Johns Hop- 

 kins has never been large ; but the teachers continue to offer varied 

 advanced courses attractive to a superior class of students, and 

 those who graduate in this subject are not often obliged to wait for 

 a vocation. In addition to the usual number of mathematical lec- 

 tures, stated in the appendix, there has been a noteworthy advance 

 during the past year in the facilities for the study of astronomy, 

 theoretical and practical, and there has been a considerable increase 

 in the number of students. 



An observatory for instruction is now provided. Besides the 

 telescope mentioned in the last report, the university has purchased 

 a meridian circle (made by Messrs. Fauth & Co. of Washington), 

 with collimators, mercury basin, and other appliances. To receive 

 this instrument, a special structure has been built adjacent to the 

 physical laboratory. A class in practical and theoretical astronomy 

 has been organized under the guidance of Prof. Simon Newcomb, 

 for many years connected with the Naval Observatory in Washing- 

 ton, and now superintendent of the United States ' Nautical Al- 

 manac' During the coming year he will be assisted by Mr. 

 Charles A. Borst, lately one of the astronomical observers of Hamil- 

 ton College, who has received the appointment of a fellow. 



From these statements it is apparent that the university is now 

 provided with the most important of the astronomical apparatus sug- 

 gested many years ago by Professor Newcomb, in one of his public 

 lectures, as desirable for the practical instruction of astronomers. It 

 has also the qualified teachers, and a company of students has begun 

 the prescribed course. The further development of this depart- 

 ment of study will be watched with great interest. Its distinctive 

 character is its adaptation to the needs of young men, already pro- 



ficient in mathematics, who need to be trained in the methods of 

 astronomical inquiry, and who want easy and constant access to 

 suitable instruments, as they have in the laboratories of chemistry 

 and physics. 



One leading idea of the work is to associate with the technical 

 study of the subject a greater breadth of culture than can readily 

 be gained by the student whose attention is wholly occupied by 

 practical work in the observatory or the field. It is therefore in- 

 tended that all students taking the doctor's degree in astronomy as 

 their principal subject, shall have an understanding of the historic 

 development of the science since its beginning, of the additions 

 made to it by its leading cultivators, of the mathematical theories 

 of the celestial motions, and of the practical use of the most impor- 

 tant astronomical instruments. 



The American Journal of Mathematics, of which Professor 

 Newcomb is editor, and Associate Professor Craig the assistant 

 and managing editor, has completed its tenth volume, and an index 

 of the contents of the entire series has been prepared for publica- 

 tion. Eight of the contributors to the tenth volume are Americans; 

 four reside in England ; four in France ; and one each in Canada, 

 Italy, and Germany. 



The mathematical staff remains as it has been for several years 

 past, Drs. Stoiy, Craig, and Franklin being associated with Pro- 

 fessor Newcomb. 



The new physical laboratory justifies the expectations which led 

 to its construction, not merely in view of the increased facilities it 

 affords for instruction, but also for the greater efficiency with which 

 investigations are carried on. 



During the past year. Professor Rowland has continued to de- 

 vote much attention to the study of the solar spectrum, and the 

 preparation of a new edition of his photographic map. The new 

 ruling-engine, which was completed a year ago, has been placed in 

 the vault prepared for it, where the temperature is equable ; and, 

 after months of laborious adjustments and connections, the ma- 

 chine has been so perfected that it rules gratings of the largest size, 

 surpassing in definition any that have been obtained before. Sev- 

 eral concave gratings six inches in diameter, and with a radius of 

 more than twenty-one feet, have been ruled with from ten to twenty 

 thousand lines to the inch, and they have been mounted in a large 

 room especially adapted to their service. It is chiefly due to the 

 excellence of these gratings that the new photographic maps are so 

 superior to the old. Something is due also to the constant atten- 

 tion Professor Rowland has given to photographic methods, and to 

 his skill in making dry plates, simple and orthochromatic. The re- 

 sult of this long and laborious preparation has been the production 

 of a map, soon to be published, of the normal solar spectrum, ex- 

 tending from the extreme ultra-violet (down to and including B) to 

 wave-length 6950. 



The director of the laboratory has been greatly favored in the 

 prosecution of his work by the services of the associate professor 

 in physics. Dr. Kimball, who has given for several years past the 

 general course of instruction, and has personally guided the labora- 

 tory-work of the students. 



The special course of instruction in electricity and magnetism 

 has been in charge of Dr. Duncan, and it has been found to meet 

 the wants of students who have an aptitude for both mathematical 

 and experimental work. Four such persons, after a special course 

 of study extending through two years, and after satisfactory final 

 examinations, received special certificates at Commencement. 



With the unusual facilities now enjoyed by Professor Rowland, 

 it is natural that his principal work during the past year has re- 

 lated to the nature of light. Under his guidance, progress has 

 been made in determining the absolute wave-length of light, and 

 the relative wave-lengths of lines in the ultra-violet portion of the 

 solar spectrum. The spectrum of hydrogen has been studied under 

 various conditions of excitement and pressure ; and the spectra of 

 zinc, cadmium, and magnesium have been studied photographically 

 and the wave-lengths measured. So, also, various bands of the 

 carbon spectrum from the electric arc have been investigated, an 

 algebraic expression of the relation between their wave-lengths has 

 been obtained, and the coincidence of the bright Imes of the carbon 

 spectrum with the dark lines of the solar spectrum has been veri- 

 fied. Additional measurements have been made on the displace- 



