Report of the Kew Committee. 



451 



on the corrections to be applied to Pendulum Observations printed in 

 the "Proc. Roy. Soc," vol. xvii, p. 488. 



It is there stated, on p. 489, that the observations were made with a 

 reversible pendnlnm, and on p. 497, with Kater's invariable pendulum. 



After a careful investigation the Committee find that only one 

 pendulum was employed throughout the whole series of experiments, 

 and that pendulum was Kater's convertible pendulum, designated in 

 the Royal Society Catalogue of Scientific Apparatus as " the basis or 

 the present system of British Weights and Measures." 



The original observations stated in the paper to be preserved at the 

 Kew Observatory cannot at present be found, and the authors are 

 unable to afford the Committee any information as to what has become 

 of them. 



Verifications. — The following magnetic instruments have been veri- 

 fied, and their constants have been determined : — 



A Dip-circle, by Barrow and Co., for the Austro-Hungarian 

 Government. 



A Dip-circle, by J. Dover, for Dr. Guido Schenzl, Budapest. 



A pair of Dipping-needles for Professor Smirnow, Kasan. 

 There have also been purchased on commission and verified : — 



A Unifilar, Dip-circle, and Pox Circle, together with the 

 apparatus for the determination of temperature and in- 

 duction co-efficients of Magnets, for Professor Greene, Bureau 

 of Navigation, Washington. 



A Unifilar for Professor Houzeau, Brussels Observatory. 



A Unifilar and Dip-circle for Professor Young, Princetown, 

 United States. 



A Unifilar for Senhor Capello, Lisbon Observatory. 



A Bifilar for Captain Wille, Norwegian Navy. 



A Dip-circle for Lieutenant van Hasselt, Utrecht. 



A pair of Dipping-needles for Professor Ferrari, Rome. 



And a Tabulator for Don Cecilio Pnjazon, San Pernando. 



There are at present undergoing verification a Dip-circle for 

 Dr. Mielberg of Tifiis, and a Dip-circle for Mr. Casella. 



Although there has been a slight falling off in the total number of 

 barometers verified as compared with last year, yet as regards ther- 

 mometers the result is highly satisfactory, the number of these 

 instruments having considerably increased. This is due to the great 

 demand for verified clinical thermometers. 



The branch still continues under the charge of Mr, T. W. Baker, 

 who is assisted by Messrs. J. Poster, T. Gunter, and C. Taylor. The 

 following are the numbers of instruments examined : — 



