210 REPORT—1899. 
north-west these effects would be reversed. The only effect at Zavalita, 
near Oaxaca, on January 24, was to crack walls, and to bring down a load 
of loose rock at the entrance to a mine tunnel, and in this way it acted 
as a service. In Oaxaca the intensity of local shocks is remarkably 
variable at short distances. 
The conclusion we arrive at from the above notes is that we 
have to deal with the shock felt severely in Mexico at 5.9 p.m., or at 
llh. 45m. 3ls. G.M.T. The time at the origin would be about 2m. 
earlier than this, or 11h. 43m. 31s. 
Velocities of transit, on the assumption that the disturbance originated 
at 23h, 48m. 31s. 
Velocities in kms. 
Time of Transit Length of path per sec. 
Place IP SEs L.W.’s 
Tees Ue L.W.’s | Degrees| Are | Chord |————__ — 
Are |Chord| Are 
M. Ss. M. S. KMs. | KMS. 
Shide. “ 411 51 11 80 8880} 8170] 35 32 2:5 
Kew . ; 3 53o0r| 5] 59 80 8880} 8170) 38 or) 350r)| 2°6 
12 53 f1°5” | 105 
Nicolaiew . cy) LA sell 28 29 100 |11100|) 9744) 13:1 | 11°5 6-42 
Rocca di Papa . | 16 21 —_ 92 |10212) 9150/ 10-4 9°3 — 
Catania . © oe Ss: le — 97 |10767| 9526] 9°8 87 > 
Toronto . : 6 53 23.39 30 3330| 3292] 8:0 Go 2:3 
Victoria, B.C. . 7 36 20 39 34 3774| 3719! 8:2 8-1 3:0 
Trieste 5 » | d4e53 64 21 91 |10101| 9072} 11°3 | 10:2 2°6 
Bombay . . | 14 282 — 141 +#+|15651/)11990; — — —_ 
Because the commencement of the Shide seismogram is partially 
eclipsed by air tremors, there is no certainty in the determination for the 
time of transit of the P.T.’s. The Kewseismogram is perfectly clear, and 
shows a very small movement, commencing at 23h. 47m. 24s., which nine 
minutes later is reinforced by slightly larger tremors. The commence- 
ment of this second group leads to the determination of the velocities 
11:5 and 10°5 kms. per second. Records from Shide, Kew, Toronto, and 
Victoria, which relate to large waves, are distinctly comparable, and the 
resulting velocities are fairly in accord to what previous investigations 
would lead us to expect. The velocities obtained for the preliminary 
tremors are, however, apparently too high, and suggest that the time 
determined for the origin of the shock is a little late. When more defi- 
nite information is obtained from Mexico this may be altered. 
The amplitude of the first maximum and the time interval to its ‘ echo.’ 
Interval Amp. 
M 8. MM 
Shide 3 : 5 : : ; ; eas ee) 6 
Kew : . 3 : E 3 : : ‘ > 16F 30 BW) 
Toronto . bo Oo Tb 
Victoria . 4 30 17 
A good seismogram has been received from Swarthmore, Penn., 
U.S.A., but its time scale has not arrived in time for publication. 
