TIME OF EARTHQUAKE : RATE OF PROPAGATION. 295 



M.S. 



These give intervals— Dehra Dun to Barrackpur 5-3 



Do. Kodaikanal 10-22 



Do. Toungoo 8-17 



or separately for the three observers ; 



H. S. Mean of h and 8 



Dehra Dun— Barrackpur. T. 4-29 5-17 4-48 



M. 4-57 5-4 5-0 



0. 5-2 5-22 5-12 



Do. —Kodaikanal T. 9-57 10-10 10-7 



M. 10-8 10-50 10-29 



O. 9-57 10-57 10-27 



Do. —Toungoo. T. 8-17 



M. 8-8 



O. 8-28 



II. — Measurement of time interval between apex (a) of dicturbance and time ci 



shock. 



(1) Absolute time of apex of disturbance (a) — 



Dehra Dun. Barrackpur. Kodaikanal. Toungoo 



Thomas . 9-12-27 9-12-22 9-12-5 9-11-7 



Mozumdar . 9-12-17 9-11-55 9-12-36 9-11-15 



Substracting the values of each" observer for the time of principal shock we get 



Dehra Dun. Barrackpur. Kadaikanal. Toungoo. 



Thomas . 3-0-41. 2-55-43. 2-50-13. 2-51-4. 



Mozumdar . 3-0-40. 2-55-27. 2-50-29. 2-51-30. 



This gives times for interval. — 



M. S. 



r T. 4-58. 

 Dehra Dun — Barrackpur < 



(.M. 5-13. 



f T. 10-28. 

 Do. — Kodaikanal -\ 



Cm. lo.ii. 



T. 9-37. 



Do. — Toungoo 



fT. 9-37. 

 CM. 9-10. 



(2) Direct measurement of time interval — 



Dehra Dun. Barrackpur. Kodaikanai. Toungoo. 



Thomas 3-0-32 2-55-18 2-50-10 2-51-0 



Mozumdar 3-0-28 2-55-25 2-50-24 2-51-5 



