OBITUARY NOTICES. xill 
ceeded where others failed, and in the course of his study in 1877 
invented the spherometer caliper. In 1879 he discovered the theory 
of the focal curve of achromatic telescopes. In 1876 he set up the 
Government astronomical exhibit at the Centennial Exposition in 
Philadelphia, Pa. In 1878 he observed the transit of Mercury at 
Austin, Texas, and the total solar eclipse at Creston, Wyoming, in 
July of that year, 1878. He carried on extensive experiments in 
astronomical photography, and in 188r to 1883 was engaged in re- 
ducing the zones of stars observed by Capt. Gillin at Santiago, 
Chile, in 1849 to 1852. In 1888-9 and 1890 he gave much time to 
the preparation of his work on Zhe Solar Parallax and Its Related 
Constants. From 1891-1899 he was chiefly occupied in following 
the erection of the new Naval Observatory, in devising and mount- 
ing its instruments, etc., etc. In 1894 he became astronomical 
director of the Naval Observatory, with complete control of all its 
astronomical work. He also became director of the Vautical Al- 
manac in June, 1897. These offices he held until his retirement for 
age, December 17, 1899, with the rank of rear-admirgl. He was 
the author of many scientific papers and member of numerous sci- 
entific societies, President of the Washington Philosophical Society 
in 1887, and President of the American Association for the Ad- 
vancement of Science in 1893. 
Pror. J. PETER LESLEY. There are those in this audience who 
can speak more fully of this departed friend than the speaker. 
These halls knew the great geologist well. The interests of this 
Society were his. Many hours did he bestow upon its affairs, and 
about us there are many eviderces of his unselfish labors. My 
knowledge of him was very slight. I saw him frequently in the 
halls and the museum of the University of Pennsylvania, but be- 
yond the formal bow it was not my privilege to know him. In the 
September issue of the American Geologist for 1903 Our associate, 
Dr. Persifor Frazer, has recorded a picture of this successful teacher 
and investigator, from which we abstract the following facts. This 
city was Lesley’s birthplace. The natal day was September 17, 1819. 
His training was received here and in the University, where he 
completed his studies in 1838. At Princeton he studied Theology 
from 1841 to 1843, and in 1844 obtained his ministerial license, 
The year of 1844-45 he spent in study at the University of Heidel- 
berg. For five years (1846-1851) he officiated as pastor of the 
