SCIENCE. 



[N. S. Vol. IX. No. 210. 



23 Commander J. M. Gilliss, who liad 

 built the Observatory some sixteen years 

 before, was ordered to assume charge. For 

 ten years previous to his withdrawal Maury 

 had ceased to have an active interest in 

 astronomical work, and had been wholly 

 absorbed in hydrographic studies. Upon 

 the accession of Gilliss new life was im- 

 mediately infused into the institution. He 

 resumed meridian observations of the Sun, 

 Moon and planets, which had been prac- 

 tically suspended, and made it one of his 

 first tasks to press the completion of all the 

 imfinished work, which had been accumu- 

 lating since 1852. At the same time he car- 

 ried on with equal zeal the nautical work of 

 the Observatory, which the Civil "War, then 

 jast beginning, had very largely increased. 



Until June 21, 1866, when the Hydro- 

 graphic Office was ci-eated, an important 

 part of the duties of the Naval Observatory 

 had been to care for and issue to the liavy 

 all charts, sailing directions, compasses, 

 chronometers, sextants, spy-glasses and 

 other nautical instruments. At the date 

 above mentioned the care of all this ma- 

 terial, except chronometers, was transferred 

 from the Observatory, but most of it was 

 returned in 1883, and since then the Ob- 

 servatory has had charge of all nautical in- 

 struments of the Navy, except charts and 

 compasses. Since January 1, 1884, all 

 chronometers have been regularly subjected 

 to a temperature test ranging from 45° to 

 95° Fahrenheit. 



During the Civil War, from 1861 to 1865, 

 the duties devolving on the Observatory, in 

 connection with the inspection and issue of 

 all varieties of nautical instruments, were 

 especially arduous, and the constant atten- 

 tion of a number of officers was required to 

 supply each of our several hundred war 

 vessels with their needed outfits. 



Since August, 1865, in accordance with a 

 plan originated by Px'ofessor Harkness, the 

 Naval Observatory has transmitted time 



signals daily, except Sundays and holidays, 

 over the telegraph lines running into the 

 chronometer room. Up to the latter part 

 of the year 1879 these signals were t]-ans- 

 mitted by hand, but since that date they 

 have been sent by an automatic apparatus 

 in connection with the transmitting clock 

 devised by Professor J. E. Eastman. Time 

 balls in a large number of the principal cities 

 of the country are dropped by them. 



In 1862 Congress authorized the appoint- 

 ment of three civilians, called aids, to assist 

 in meeting the increased demands on the 

 Observatory on account of the war. Some 

 of the changes in the personnel during Ibis 

 period were as follows : 



Simon Newcomb was appointed Professor 

 of Mathematics, U. S. N., in 1861 ; Asaph 

 Hall, William Harkness and J. E. Eastman 

 received appointments as aids in 1862. Hall 

 and Harkness were promoted in 1863, and 

 Eastman in 1865, to be Professors of Mathe- 

 matics, U. S. N. In 1863 the Observatory 

 lost by death the gifted Professor Hubbard, 

 whose labors had been restricted for years 

 by a frail body. 



The later additions to the personnel were 

 as follows : Edgar Frisby was appointed 

 Assistant Astronomer in 1868 ; A. N. Skin- 

 ner in 1870 and H. M. Paul in 1875. 

 Frisby was promoted to be Professor of 

 Mathematics, U. S. N., in 1878, on the re- 

 tirement of Professor Yarnall. 



Soon after Gilliss' accession to the super- 

 intendency it became apparent that in order 

 to meet the demands of science the Observa- 

 tory needed a first-class meridian circle, 

 and he took steps to remedy this defect in 

 its equipment. The result was the sale 

 of the small Ertel meridian circle, and the 

 mounting in 1865 of a Pistor and Martins 

 meridian circle 8.52 inches' aperture. The 

 Ertel ti'ansit instrument was moved to the 

 east wing and the new meridian circle took 

 its place in the west wing. 



In 1873 the Observatory received the 



