SKETCH OF CHESTER S. LYMAX. 121 



Physics in 1884, but still retains the Sheffield professorship of Astron- 

 omy, of which science he has been the instructor from the organiza- 

 tion of the school in 18G0. 



He spent the summer of 18G9 in Europe, for the purpose of col- 

 lectino- mechanical and physical apparatus for the school, and of visit- 

 ing scientific institutions. He has been a contributor to " The Ameri- 

 can Journal of Science," " The New-Englander," and other periodicals, 

 and is the originator of various useful inventions, among which are 

 the wave apparatus known by his name, patented and manufactured 

 by Messrs. Ritchie & Sons, of Boston, and a pendulum apparatus for 

 describing Lissajou's acoustic curves, constructed several years in ad- 

 vance of a similar apparatus made in London by Tisley & Spiller. 



Professor Lyman is the original inventor of the combined transit 

 instrument and zenith telescope for determining latitude by Talcott's 

 method. This instrument Avas designed and mainly constructed in 

 1852-53, and numerous observations together with a description of 

 the instrument were published in " The American Journal of Science " 

 and elsewhere, some ten years before the construction and published 

 account of a like instrument by Davidson.* His aptitude in practical 

 mechanics was of much service to him in devising and constructing 

 apparatus for the lecture-room. 



Professor Lyman has been actively interested from the first in the 

 establishment of the Yale Observatory, and is one of its board of man- 

 agers. His attention has been much given also to practical horology, 

 and some improvements of his in escapements and compensation pen- 

 dulums have proved practically valuable. He was the first to observe 

 Venus as a delicate ring of light when very near the sun in inferior 

 conjunction, as in December, 1866, and also before and after the tran- 

 sit of Venus in 1874. 



He is a member of various scientific and literary bodies, among 

 them the British Association for the Advancement of Science, and was 

 for twenty years President of the Connecticut Academy of Arts and 

 Sciences. 



Mr. Lyman's life-work has been mainly teaching. He has the 

 quality so necessary in a successful instructor — that of explaining dif- 

 ficulties with great clearness and patience. His uniform practice of 

 treating his students as gentlemen rather than school-boys, and trust- 

 ing to their sense of honor, has gained for him their universal respect 

 and affection. 



* This instrument has been in use for many years, and known by Lyman's name, in 

 the governmental survey of India. 



