342 JOSEPH wrNi,0CK. 



attachment for transmitting time-signals, a Frodsham sidereal clock, a 

 Frodsham hreak-circuit sidereal chronometer (the original device of 

 Mr. AViiilock), a mean-tirae chronometer, a thermometric chronome- 

 ter, a photographic telescope of long focus, a Russian transit, made in 

 the workshop of the Pulkowa Observatory, a Zolluer astrophotometer, 

 a large RuhmkortF coil, various spectroscopes and self-recording 

 meteorological instruments, — all this rapid increase of resources, 

 while it added to the power, greatly multiplied the responsibilities of 

 the Director. The costly transit-circle, though constructed upon the 

 best models and by the most excellent artists, had always proved a 

 failure and a disappointment ; as ]Mr. Bond supposed, from fatal injuries 

 which it received in its transportation. Though it was useful as a 

 transit-instrument, implicit reliance could not be jilaced in it as a 

 circle. The consequence was, that the great equatorial was too fre- 

 quently called away from its legitimate woi'k to do the duties which 

 belonged properly to the circle. Mr. Wiulock was not long in in- 

 spiring the friends of the Observatory with that large measure of con- 

 fidence in his cai^acities and his sound judgment which prompted them 

 to contribute over $12,000 for the purchase of a new meridian circle. 

 In the autumn of 1867, Mr. Wiulock went to Europe, and spent four 

 months in visiting the principal observatories, and acquainting himself 

 with the latest improvements in instruments, and especially in circles. 

 Having studied the advantages and the defects in the highest class of 

 meridian instruments, he blindly copied no one of them ; but suggested 

 valuable modifications, with the view of securing greater stability, 

 increased precision of movement, and the most complete facility of 

 observation. The improvements which he suggested were warmly 

 approved and promptly adopted by the artists whom he prefei'red, 

 Troughtou and Simms of London ; his modifications of the old con- 

 struction have been fully justified by the results since the new circle 

 has been put to work, and other astronomers have given the best 

 indorsement by copying them. The eminent astronomer and mathe- 

 matician, .7. C Adams, now President of the Royal Astronomical 

 Society, oidered a circle from the same artists and of the same jiattern 

 for Cambridge, in England. In November, 1870, when the new 

 instrument was ready for use, Mr. Wiulock turned it upon the zone of 

 stars between 50° and 55° of north declination. AVhen the whole 

 field of observation was divided between the different members of the 

 Astronumische GeseUschaft, this was the share which fell to the Obser- 

 vatory of Harvard College. Already 15,000 observations have been 

 made upon the zone-stars, and in two years more the great work will 



