January 6, 1899.] 



SCIENCE. 



5 



Observatory followed Euglisli precedent, 

 and was supplied with a mural circle which 

 remained its principal declination instru- 

 ment until 1865. The remaining equipment 

 was the Ertel transit instrument, of first- 

 class construction, but without horizontal 

 collimators and azimuth marks ; the small 

 Ertel meridian circle, which had been 

 ordered by Gilliss for the Observatory on 

 Capitol Hill ; the Pistor and Martins prime- 

 vertical transit instrument, identical in de- 

 sign with the similar instrument at Pulkowa; 

 and the Merz and Mahler equatoi-ial refract- 

 ,ing telescope. The Ertel meridian circle 

 showed such serious defects of construction 

 that it was subsequently sold, and the Merz 

 and Mahler equatorial was much smaller 

 than the refractors at Pulkowa and Harvard 

 College Observatories, one of which was 

 erected a little before and the other a little 

 after that at the ISTaval Observatory. It 

 may also be mentioned that instead of mak- 

 ing the walls of its observing rooms of 

 brick, the Naval Observatory might advan- 

 tageously have followed the example of Pul- 

 kowa by making them of wood, the use of 

 sheet metal for such purposes being then 

 unknown. 



ISTow, for a passing glance at the person- 

 nel of the astronomical corps, which was 

 composed of three more or less distinct 

 classes, namely, line officers and staff ofB- 

 cers of the United States ISTavy and civilians. 

 After years of persistent labor, Gilliss had 

 created an astronomical observatory only 

 to have it snatched from his grasp when it 

 was ready for work. Lieutenant Matthew 

 F. Maury, who was ordered to take charge 

 of the new ' Depot of Charts and Instru- 

 ments ' as its Superintendent on October 1 

 1844, was then thirty- eight years old. He 

 was possessed of great energy, together 

 with a high degree of native ability, and 

 was well versed in naval affairs, but was 

 very scantily informed in regard to the 

 great advances in astronomical science 



which had recently been made in Europe. 

 From the line of the navy three lieutenants 

 and six midshipmen were detailed as his 

 assistants. These gentlemen entered upon 

 their work with energy, but their tour of 

 duty was so limited by the rules of the 

 Navy Department that they were obliged 

 to return to their nautical work when they 

 had barely familiarized themselves with 

 their astronomical duties. Among their 

 names will be recognized many who at a 

 later date attained distinction during the 

 Civil War. To these line oflicers were 

 added Professors of Mathematics CoiSn, 

 Keith and Hubbard, who were staff offi- 

 cers in the Navy. The corps of Professors 

 of Mathematics in the United States Navy 

 was originally created to supply instructors 

 for midshipmen afloat and ashore, and all 

 of them served in that capacity, until the 

 founding of the Naval Academy in 1845 

 closed their seafaring career and gave the 

 Navy Department an opportunity to utilize 

 a part of the corps in other duties. Pro- 

 fessor Coffin had instructed midshipmen on 

 shipboard for some half dozen years before 

 he was ordered to assist Lieutenant Gilliss 

 in 1843 in fitting up the new Observatorj'. 

 Hubbard, a recent graduate of Yale Col- 

 lege, was appointed Professor of Mathe- 

 matics, U. S. N., in 1845, and was im- 

 mediately ordered to the Observatory. 

 Keith, who had just graduated from Mid- 

 dlebury College, Vt.,- received his ap- 

 pointment as Professor of Mathematics, 

 U. S. N., in 1847. These gentlemen were 

 each possessed of a high degree of mathe- 

 matical ability and wei-e destined to leave 

 a lasting impress on the work of the 

 Observatory. At that time the only civil 

 appointee attached to the Observatory was 

 Mr. Sears Cook Walker, who was em- 

 ployed as a computer and observer. He 

 was one of the ablest, and certainly the 

 most experienced, of the corps of astrono- 

 mers, but unfortunate differences with 



