REPORT OF THE KEW COMMITTEE. xli 



establishment of a Magnetic Observatory here, in connexion with observa- 

 tions on meteorology and atmospheric electricity, and deferred writing until 

 I was in a position to acquire the instruments necessary. 



" You said in your communication that '£80 or thereabouts was required;' 

 and you were kind enough to add, with a spirit of generosity I could not 

 expect, 'that every care should be taken to superintend the construction of 

 such instruments, to verify them, and to determine their constants, and have 

 them carefully packed and sent out.' 



" The object of the present letter is to ascertain, 1st, the exact cost (if pos- 

 sible); 2nd, to whom the amount shall be forwarded; 3rd, when the instru- 

 ments would probably be ready ; 4th, a short list of what are to be sent. 



" I feel that I am asking too much from you ; but a knowledge of your 

 devotion to a science which you have so much extended, makes me feel less 

 diffident, and I have thrown myself upon your kindness. 



" I have also to acknowledge the receipt of a Book of Instructions, &c, 

 with thanks. 



" So soon as I get a reply from you, I will at once transmit the amount 

 with the order, and submit a plan of the building. 



" Believe me to remain, with great consideration and respect, 



" Yours faithfully, 

 (Signed) " C. Smallwood." 



" General Sabine, London." 



Instruments to meet this request are in preparation. 



The Committee have thought that it might not prove uninteresting to the 

 members of the British Association, if, in this Report, a short description 

 were given of the Kew Observatory, and of the nature and amount of work 

 which is accomplished therein. 



The Observatory is situated in the middle of the old Deer-park, Richmond, 

 Surrey, and is about three-quarters of a mile from the Richmond Railway 

 Station. Its longitude is 0° 18' 47" W., and its latitude is 51° 28' 6" N. It 

 is built north and south. The repose produced by its complete isolation is 

 eminently favourable to scientific research. In one of the lower rooms a set 

 of self-recording magnetographs, described in the Report of the last meeting 

 of this Association, is constantly at work. These instruments, by the aid of 

 photography, furnish a continuous record of the changes which take place in 

 the three magnetic elements, viz. the declination, the horizontal force, and the 

 vertical force. The light used is that of gas, in order to obtain which, pipes 

 have been carried across the Park to the Observatory, at an expense of ^€250, 

 which sum was generously defrayed by a grant from the Royal Society. 



Attached to this room is another, of a smaller size, in which the necessary 

 photographic operations connected with magnetography are conducted. 



In the story above the basement, the room by which the visitor enters the 

 Observatory is filled with apparatus. Much of this is the property of the 

 Royal Society, and some of the instruments possess a historical value ; for 

 instance, the air-pump used by Boyle; and the convertible pendulum designed 

 by Captain Kater, and employed by him, and subsequently by General Sabine, 

 in determining the length of the pendulum vibrating seconds. 



An inner room, which opens from this one, is used as a library and sitting- 

 room, and in it the calculations connected with the work of the Observatory 

 are performed. In this room dipping-needles and magnets, which it is neces- 

 sary to preserve from rust, are stored. Here also the MS. of the British 

 Association Catalogue of Stars is preserved. 



A room to the east of this contains the standard barometers, and the appa- 



