512 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1915. 



Up to the age of 20 Gill's scientific interests appear to have had no 

 particular inclination to astronomy, but in 1863 he became desirous 

 of securing an accurate time service at Aberdeen, Encouraged by 

 a visit to Prof. Piazzi Smyth at Edinburgh Observatory, he suc- 

 ceeded in interesting Prof. David Thomson in his efforts. There 

 was at that time an old observatory at King's College, Aberdeen. 

 Together the two men unearthed and set up in adjustment a portable 

 transit instrument which had long been disused, the sidereal clock 

 was overhauled and fitted with contact springs for the electrical con- 

 trol of other clocks, and the observations for time determination now 

 became the chief occupation of Gill's leisure evenings. 



It was not long before he began to seek for an instrument which 

 would give him a wider scope for astronomical work. He met with 

 a second-hand silver-on-glass mirror of 12 inches aperture and 10 

 feet focal length. The task of mounting this equatorially gave him 

 the first opportunity of displaying that skill in instrumental de- 

 signing for which he afterwards became so famous; and the whole 

 mounting was made from his working drawings. He made the driv- 

 ing clock with his own hands. 



Among the chief results obtained with this telescope were some 

 excellent photographs of the moon. At that time Lord Lindsay 

 (son of the Earl of Crawford) was planning to erect an observatory 

 at DuiB Edit, 13 miles from Aberdeen. Having seen these photo- 

 graphs, he visited Gill in order to see his instruments and methods 

 of work. The acquaintance thus formed led to Gill's receiving early 

 in 1872 an invitation to take charge of the Dun Echt Observatory 

 that was about to be erected. 



At this time Gill was actively at work all day, his father having 

 retired, leaving the business in his hands; it was only his evenings 

 that could be devoted to scientific pursuits. He had married in 1870, 

 and was living in Aberdeen near his little observatory. To accept 

 Lord Crawford's offer meant the giving up of a fiourishing business 

 and a heavy pecuniary sacrifice ; but by now astronomy was claiming 

 him> irresistibly, and he made the choice without hesitation. The 

 business that he now relinquished had never been congenial to him; 

 but the time he had devoted to the clockmaker's art had not been 

 wasted, for it is reasonable to believe that his natural mechanical 

 genius was in no small measure fostered by this early training. 



Gill's direction of the Dun Echt Observatory lasted from 1872 to 

 1876. It was his task to design and install the fine equipment that 

 was rapidly acquired — for him a foretaste of the similar work he 

 was afterwards to carry out at the Cape. But this period of his life 

 is chiefly remembered not for observations made at Dun Echt but 

 for an expedition to the island of Mauritius on the occasion of the 

 transit of Venus, 1874. It was in preparation for the work at 



