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order. In 1848 lie proposed to erect a transit circle. Other great 

 instruments followed, and in 1855, when the want of an equatoreal 

 was pointed out, the Board of Visitors warmly supported his views. 

 In the summer of 1860 the instrument was in a state fit for use 

 Enough has now been said to show that by his energy and per- 

 severance the Royal Observatory has been equipped with the most 

 admirable instruments which could be obtained. As early as De- 

 cember, 1849, the Astronomer Royal made an oral statement to the 

 Astronomical Society on the method of observing and recording trans- 

 its lately introduced in America. He explains how a measure of its 

 accuracy, as compared with Greenwich observations, had been made, 

 and, after pointing out some defects, he thought the possible advan- 

 tages so great that he contemplated adopting it at the Royal Obser- 

 vatory. In this report for 1854 he tells us that the new barrel- 

 apparatus had been practically brought into use, not, however, 

 without a succession of difficulties, whose causes it was sometimes 

 very hard to discover. He concludes by remarking that the method 

 is troublesome in use, and consumes much time in preparation, but 

 that, amongst the observers who use it, there is only one opinion on 

 its astronomical merits, viz., that, in freedom from personal equation 

 and in general accuracy, it is very far superior to the observations by 

 eye and ear. 



In 1846 Mr. Airy was one of three Commissioners appointed by the 

 Queen to report on the proper gauge for railways. The Commis- 

 sioners considered that the chief advantage of the broad gauge lay in 

 the speed of the trains, while in the conveyance of goods and the 

 cost of outlay the narrow gauge was the superior. For these and 

 other reasons they recommended that the present narrow gauge 

 should by statute be that of all railways to be constructed in future, 

 After examining and rejecting several ingenious inventions by which 

 the same carriage could be made to run on both gauges, they also 

 recommended that some equitable means should be found by which 

 the railways then on the broad gauge could be reduced to the narrow. 

 This second recommendation was not, however, adopted by the legis- 

 lature. In 1858 Professor Airy was one of the Commission on the 

 Ordnance Survey appointed to consider, amongst other questions, 

 the scales on which the maps were to be constructed. 



In the 1 Monthly Notices ' for November, 1846, there is a memoir 

 by the Astronomer Royal, giving his own, Professor Challis', and Mr, 

 Adams' separate accounts of the discovery of Neptune. Mr. Airy 

 remarks that in the whole history of astronomy there is nothing com- 

 parable to this discovery ; TTranus, Ceres, Pallas, and other planets 

 were discovered by observation, but, in the case of Neptune, mathe- 

 maticians stated beforehand that a planet would be found exactly in 

 a certain place and presenting exactly a certain appearance. In that 



