342 JOSEPH WLNT^OCK. 



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

 Frodsham break-circuit sidereal chronometer (the original device of 

 Mr. Winlock), a mean-time chronometer, a thermometric chronome- 

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

 the workshop of the Pulkowa Observatory, a Zollner astrophotometer, 

 a large Ruhmkorff coil, vai'ious 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 it.s transportation. Though it was useful as a 

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

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

 quently called away from its legitimate work to do the duties which 

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

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

 fidence in his capacities 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. Winlock 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. 

 Havinw 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 preferred, 

 Troughton 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. Tiie eminent astronomer and mathe- 

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

 Society, ordered a circle from the same artists and of the same pattern 

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

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

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

 field of observation was divided between the diflferent members of the 

 Astronomische Geselhchaft, 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 



