January 6, 1899.] 



SCIENCE. 



retary of the Navy, July 28, 1846. Speak- 

 ing of the regular work upon the Sun, Moon 

 and planets, he adds : " A regular series of 

 observations is continued on these objects 

 and the time which is not occupied in the 

 round with them has, vi^ith your approval, 

 been devoted to cataloguing ; to this end a 

 regular and sj'stematic exploration of the 

 whole heavens from 45° south has been 

 commenced, with the intention of penetra- 

 ting with the telescope every point of space 

 from that parallel of declination up to the 

 north pole, and of assigning position to every 

 star, down to the 10th magnitude, that shall 

 pass through the field of view." The amount 

 of labor involved in this colossal under- 

 taking was entirely beyond the capacity of 

 anj' one observatory to accomplish in a 

 generation. Maur}- would never have un- 

 dertaken it if he had possessed an intimate 

 knowledge of the herculean labor in respect 

 to observation and computation which its 

 execution demanded. The result was that 

 the observation of the zones was continued 

 with some degree of energy through the 

 years 1846, '47, '48 and '49 with the transit 

 instrument, the mural circle and the merid- 

 ian circle, by some eleven different observ- 

 ers, two of whom were experienced, and the 

 remainder quite inexperienced. The num- 

 ber of observations accumulated unreduced 

 in these four years was fully 38,000. 

 Maury did not publish any results until 

 1860, when he issued the meridian circle 

 zones observed in 1846, containing about 

 4,000 observations. The publication of the 

 remaining zone work was delayed until 

 1873, when it was printed under the super- 

 vision of Professor Asaph Hall, who re- 

 marks : " On account of the inexperience of 

 some of the observers and the lack of good 

 organization these observations contain 

 many errors, and the whole woi'k needs a 

 careful revision." To furnish material for 

 this revision, four hundred and fifteen zero 

 stars were selected by Professor Hall from 



the zones, and their places have since been 

 determined, but as yet the revision has not 

 been accomplished. In contrast with this 

 we may recall that during the decade 1850 

 to 1860 Argelander, of the Bonn Observa- 

 tory, in accordance with a carefully con- 

 ceived plan, observed and published the 

 approximate positions of moi-e than 450,000 

 stars of the first nine magnitudes between 

 23° of south declination and the north pole 

 of the heavens. Maury failed because his 

 scheme was entirely too herculean to be ac- 

 complished with the means at his command, 

 while Argelander achieved success by bring- 

 ing the scope and precision of his work 

 within the limits possible of execution. 



A review of this period would be incom- 

 plete without a reference to the invention 

 of the chronographic method of registering 

 star transits and the general application of 

 electro-magnetism to the transmission of 

 time signals for the determination of differ- 

 ences of longitude. Soon after the inven- 

 tion of the telegraph several persons at 

 about the same time conceived the idea of 

 applying its fundamental principles to the 

 transmission of clock signals and the regis- 

 tering of star transits. Among them were 

 Walker, Bache, Bond, Mitchell, Saxton and 

 Locke. Lieutenant Maury became inter- 

 ested in the labors of the last-named gentle- 

 man, and induced Congress to appropriate 

 $10,000 on March 3, 1849, to pay Dr. Locke, 

 of Cincinnati, for the construction and use 

 at the National Observatory of a magnetic 

 clock, a fillet chronograph and a cylinder 

 chronograph. These instruments, although 

 not perfect in details, embraced the essential 

 features of the chronographs in actual use 

 at the present time. 



We come now to the third period of the 

 history of the Observatory — namely, from 

 Maury's resignation to the removal to the 

 new site. On April 20, 1861, Maury sud- 

 denly resigned his commission and went 

 south to join the Kebellion, and on April 



