Report of the Kew Committee. 



319 



nor connexions having needed the slightest attention. The direction 

 gear has, however, occasionally required readjustment of its orienta- 

 tion after strong winds have blown, and is now undergoing alteration. 



Hand Anemometers. — A number of these instruments, intended to 

 show the velocity of the wind during a brief period of observation, 

 have had their scale values determined by direct comparison with the 

 Standard Anemograph of the Observatory. 



Range-finders. — Facilities have been afforded to Dr. Ristori, 

 F.E/.A.S., by the employment of the Cooke apparatus, for the purpose 

 of graduating some new range-finders invented by Mr. Nordenfeldt, 

 and constructed by Mr. Casella, the cost of the experiments being 

 defrayed by the inventor. 



V. Verification of Instruments. 



The following .magnetic instruments have been verified, and their 

 constants determined : — 



2 Unifilar Magnetometers and an Inclinometer for Elliott 



Brothers, London. 

 1 Unifilar Magnetometer with two Collimating Magnets, and 



an Inclinometer for the Admiralty, London. 

 1 small-pattern Fox Circle for the Bureau of Navigation, 



United States Government, and an ordinary Inclinometer 



for Dover, Charlton. 



3 pairs of Inclinometer Needles have been purchased on commission 

 and verified for Dr. Wild and the Mauritius Observatory. 



One Unifilar and an Inclinometer are at present undergoing 

 examination for the Falmouth Observatory. 



The total number of other instruments tested in the past year was 

 as follows : — 



Barometers, Standard 54 



,, Marine and Station 98 



Aneroids 104 



Total 256 



Thermometers, ordinary Meteorological 1825 



Standard 143 



Mountain 13 



Clinical 8238 



,, Solar radiation 49 



Total 10268 



VOL. XXXIX. T 



