414 



MR J. J. MANLEY: OBSERVATIONS ON THE 



instrument had been placed unsymmetrically with regard to the radiant energy 

 falling upon it. From Curve III. we infer that the new position which the balance 

 occupied during the experiment was perfectly satisfactory and almost ideal. 



Time in Seconds 



40 8O 120 160 ZOO 



3OO 



FigZHL 



400 



C 



008 



006 



L'OO* 



002 



.20*OOO 



008 



006 



00* 



.002 



.20*000 



008 



COS 



OO4 



OOZ 



Z0000 C 



500 



We have deliberately refrained from introducing into this paper numerous and 

 lengthy tables of data. In place of such tables, which, in our opinion, could serve no 

 useful purpose, representative graphs of typical cases have been inserted. These 

 have the merit, not always possessed by columns of data, of revealing, almost at a 

 glance, that which it is desired to convey. It is obviously impossible and undesirable 

 to give more than a very few of the somewhat large number available for our 

 purpose. 



In conclusion, the author would express his indebtedness to the Government Grant 

 Committee of the Eoyal Society for the continued loan of certain apparatus used in 

 connection with this research. He would also acknowledge his obligations to 

 Mr. W. W. FISHER, of the Oxford University Chemical Laboratory, Messrs. BAIRD 

 and TATLOCK, and Messrs. A. GALLENKAMP and Co., all of whom very kindly granted 

 him the loan of some of their finest balances. Without their generous aid it would 

 have been exceedingly difficult to bring certain portions of this investigation to a 

 satisfactory termination. Finally, the writer's best thanks are due to Mr. R T. 

 GATHER, Fellow of Magdalen College, Oxford, for the valuable help and advice 

 which he has received from him. 



