608 Proceedings of the Royal Irish Academy. 



jSTow, 



where / is the earth's moment of inertia with respect to the axis of 

 rotation, and Vq is the earth's velocity at the equator. 

 From (-£'), which may be written 



GT=27rI, 



we have 



GST+ TSG = 0. 



Hence 



Substituting the values of 8 G^ and G, we find 



0-01776 X 3-06 X TT-eri^a^w x T 



ST^ + 



but 



Hence 



and 



or 







4: VoMa 





Fo^ 



27r 



(f; 





M= 



: -Tra^ X 5-5. 

 3 





4 VoMa = 



32 



X 5-5 X TT^a^ 

 3T ' 





0-01776 



X 3 



X 3-06 X T^x 



^w 



32 X 5-0 or 



If we express St in terms of the number of years requisite to produce 

 any given diminution 8T, in the length of the day, we have 



St= 365-25 X Tn, 



which converts {F) into 



365-25 r^?^; ^ ,„ ,. . 



