Report of the Kew Committee. 



331 



Marine Chronometers. — During the year, 9 class A and 9 class B 

 certificates have been issued with chronometers which had undergone 

 the tests, as described in last report ; one movement failed to pass the 

 trials. 



VII. Miscellaneous. 



Lens Testing. — A detailed account of the apparatus and methods 

 employed in the examination of lenses has been completed by Major 

 Darwin, and presented to the Royal Society. The paper is being 

 printed in extenso by several photographic journals. Major Darwin 

 also read a paper on this subject before the Photographic Society of 

 Great Britain, the apparatus being illustrated by means of lantern 

 slides. The Lens Testing Camera was shown at the Soiree of the 

 Royal Society, in May. 



A loan of twelve lenses, all known to be of good quality, has been 

 obtained from the Royal Engineering School at Chatham, by the kind 

 permission of the Commandant. These have been subjected to a 

 very detailed examination, the results of which will be considered as 

 standards of reference for other lenses sent here for certification. 



Experiments are in progress in the endeavour to find an object 

 more suitable for the " definition " test than the one now in use. 



Library. — During the year the library has received as presents the 

 publications of — 



37 Scientific Societies and Institutions of Great Britain and 

 Ireland, and 



106 Foreign and Colonial Scientific Establishments, as well as of 

 numerous private individuals. 



The preparation of the card catalogue of the Library is still con- 

 tinued, but confined only to such publications as relate to Meteorology, 

 Terrestrial Magnetism, and the other work of the Observatory. 



Extension of the Building. — The Chief Commissioner of Works and 

 Public Buildings having granted permission for the Committee to 

 undertake the erection of the additional story to the west wing of the 

 Observatory, as mentioned in last year's Report, and having instructed 

 Mr. Lessels, surveyor to the Board, to prepare the necessary drawings, 

 plans, &c, tenders were invited from the principal local builders for 

 the work. That of Messrs. J. Dorey and Co., of Brentford, for £540, 

 was accepted, and operations were commenced on July 15. They 

 have now been completed, under the superintendence of Mr. Chart, 

 H.M. Commissioners' Clerk of Works for the Hampton Court and 

 Kew District, and Mr. Allen, his assistant. 



The cost of the operations being a heavy charge on the funds at 

 the present disposal of the Committee, they made application to the 

 Royal Society for a loan of £400, which was liberally granted. 



