54 MODERN SEISMOLOGY 
For P. 
A P S Y e e 
in kilometres. | in seconds. | in seconds. 6/2. peels computed. observe 
oO fo) (0) 0750) 0° 22m 
500 69 124 PD Tes}! II 23 
1,000 136 244 4 30 21 27 
1,500 199 356 6 45 30 32 
2,000 257 460 C) | © 37 37 
2,500 310 555 II 14 44 42 48° 
3,000 358 641 | 13° 29 49 47 44 
3,500 402 719 15 44 53 52 43 
4,000 442 789 17 59 57 54 42 
4,500 478 854 20 14 60 58 43 
5,000 512 Qg13 22120 63 60 44 
5,500 542 971 24 44 65 62 46 
6,000 572 1,028 26 59 65 62 48 
6,500 601 T,084 29 14 65 63 51 
7,000 631 I,140 Bia 2! 65 63 54 
7,500 660 1,194 33 43 66 63 58 
8,000 688 I,249 35 58 66 64 62 
8,500 716 I,301 28013 67 64 65 
9,000 743 1,354 40 28 67 65 67 
9,500 769 1,404 42 43 68 66 68 
10,000 795 1,453 44 58 69 67 70 
10,500 820 I,500 AGL 70 67 71 
II,000 844 I,545 49 28 70 68 72 
II,500 867 1,588 5I 43 71 69 72 
12,000 888 1,629 53 58 72 70 73 
I2,500 909 1,668 56 12 73 71 73 
13,000 929 1,705 58 27 74 72 74 
Let EA and EB, fig. 12, represent neighbouring paths, then 
BEC ah 
COS @=~{5 = 
ABT wi 
where V is the corresponding velocity of the wave at the sur- 
face. This important result, which applies to both P andS 
= 
FIG. 12. 
whatever be the path, is of course meaningless as applied to 
L. Since V, and V, are known we may from the time curves 
