22 Report of the Kew Committee. 



Photoheliograph. As soon as the experiments with this instrument 

 mentioned in last Report were completed it was taken down, and, on 

 application from the Astronomer Royal, intrusted to him for use at 

 Greenwich, in taking sun-pictures pending the return of the new instru- 

 ments to be used in observing the Transit of Yenus. The scale of equal 

 parts, erected on the Pagoda in Kew Gardens, in order to test the optical 

 distortion (if any) of the Kew Photoheliograph, has been taken down 

 by the direction of Mr. De La Rue, and any slight damage done to the 

 building has been made good at the expense of that gentleman, and to 

 the satisfaction of the Clerk of the Works at Kew. The scale itself has 

 been made over to the Astronomer Royal by Mr. De La Rue. 



The thanks of the Committee have been conveyed to H.M.'s Office of 

 Works for the facilities Idndly afforded for the above experiments. 



The eye-observations of the sun, after the method of Hofrath Schwabe, 

 have been made daily by Mr. Foster, when possible, as described in the 

 last Report, in order, for the present, to maintain the continuity of the 

 Kew record of sun-spots. 



An additional series of positives, from the Kew negative pictures, 

 is now being printed by a photographer, at the expense of Mr. De 

 La Rue. 



A statement, embodying the usual data respecting the spots &c. on the 

 sun's disk, has been, as usual, published in the * Monthly Notices of 

 the Royal Astronomical Society.' 



Prof. Spoerer, of Anclam, has applied for the measurements of sun- 

 spots for the months of January and February 1872, during the period 

 of his own illness ; and Mr. De La Rue has kindly promised to furnish 

 them as soon as their reduction has been effected. 



Electrometer. This instrument, the property of the Meteorological 

 Committee, which was returned for readjustment to the maker, Mr. 

 White, of Glasgow, in September 1872 (Report, 1872), is still in his 

 hands. The instrument, a self-recording one, has never yet been in 

 working order. 



Verifications. This department of the Observatory has been in full 

 activity ; and the work has increased largely as regards barometers and 

 clinical thermometers, so that almost the entire time of Mr. Baker and 

 a junior assistant is occupied therewith. 



The following magnetic instruments have been verified and constants 

 determined : 



A Unifilar for the Observatory at Manila. 



Prof. Clifton, F.R.S., Oxford. 

 Dr. E. van Rijckevorsel, of Rotterdam. 



And in addition : 



A Dip-circle for the Observatory at Manila. 

 Dr. E. van Rijckevorsel. 



