172 RESEARCH 



identity, between comets and meteors, and the work 

 of the Association committee contributed to this 

 achievement in no small degree. The real paths 

 of meteors were very accurately computed by A. S. 

 Herschel, and he, in collaboration with R. P. Greg, 

 determined a considerable number of radiant points 

 which were tabulated and formed into catalogues 

 convenient for the guidance of future workers. Even 

 to-day, over forty years after the publication of the 

 final meteoric report by the Association, much of the 

 data collected and printed in the annual volumes is 

 of great interest to students and possesses an enduring 

 value. Apart from the actual importance of the 

 work accomplished by the committee, a large measure 

 of interest was attracted to this department of 

 astronomy. 1 



The measurement of lunar disturbance of gravity 

 in 1879-81 received only modest financial assistance 

 from the Association, but ( the recognition of the 

 British Association/ writes Sir Horace Darwin, 

 ' was even more important, and in my opinion little 

 or nothing would have been done without this 

 British Association committee.' An instrument, 

 slightly modifying one suggested by Kelvin, was set 

 up in the Cavendish Laboratory, and detected very 

 small alterations in the direction of gravity with 

 reference to itself. The additional conclusion was 

 arrived at that ' the instrument was always moving 

 relatively to the earth by an amount greater than 

 the expected movement due to the moon, and this 

 was due to slight earthquakes always going on.' 



1 Mr. W. F. Denning. 



' 



