166 REPORT—1899, 
In its original form the akove List did not contain records numbered 
170, 173, 176, 177, 178, 190, 191, 198, 204, 205, 206, 208, 209, 211, 212, 
218, 224, 227, 234, 236, 237, 241, 242, 243, 244, 251, 258, 261, 262, 265, 
266, 267, 268, 269, 270, 271, and 272. The reason for the omission was 
that these records were so small that it was not considered likely that 
they would be recorded at other stations. I call them the subsidiary 
list. 
Between March 18 and 21 the original list was sent to stations No. 1 
to 19,1 and also to Strassburg, Padua, Rome, Rocca di Papa, Casa- 
micciola, Catania, Potsdam, Nicolaiew, Edinburgh and Bidstone. 
On April 14 the subsidiary was forwarded to Cadiz, Bombay, Toronto, 
Potsdam, Rome, Rocca di Papa, Catania, Paisley and Kew. 
The responses have, when necessary, been reduced to Greenwich mean 
civil time, and are contained in the following tables :— 
2. England: Kew Observatory. Superintendent, Dr. Cuares Curr, F.R.S. 
Kew has met with difficulties in common with Shide, but the tremors 
have not been so frequent or pronounced. Why certain earthquakes like 
Nos. 196, 207, 214, 220, 221, 225, 246, 247, &e., were not recorded, whilst 
the amplitudes of large earthquakes are smaller than the same at Shide 
and at the same time show phases of maxima movements farther separated 
in time than they appear to be at the latter place, is difficult to under- 
stand. The most likely explanation is that at Kew the foundations of 
the instruments rise from an extremely thick bed of soft tertiary materials 
more or less saturated with water, whilst at Shide the piers rise from the 
surface of upended beds of comparatively hard, diy chalk. 
The Kew Register. 
Such a statement as ‘normal line or line, ‘2 mm. ; tremors, 0:4 mm.’ 
means that the full width of the line (not the half width) was -2 mm. when 
undisturbed, but -4mm. when disturbed. In such a case the amplitude 
would be 5 (-4—+2), or ‘1 mm. On the other hand, when it is said either 
that ‘max. amplitude = 0-9 mm.,’ or ‘amplitude = 5-5 mm.,’ it is meant 
that the half width of the central line was 0:9 in the former and 5-5 in 
the latter case. The ¢rwe amplitude would be in the former case, say, 
0‘9—«, when 2a was the undisturbed width of the line, whatever that 
might be at the time. 
At Kew variations in the full width of the line from ‘1 to ‘3 mm. are 
noticed. 
Milne Seismograph started at Kew Observatory on April 19, 1898. 
Shide Time of the ' 
No. | No, Date | Commence- Remarks: (D=duration in minutes) 
; | ment 
| 
1898. 
ieee 
1 | 195 April 25 TS Geb <9 Character slight. D=2. Faint tremors 
1ih. 14m. to 11h. 24m. 
—_— » 20 Wpye ae) Fairly well marked. D=12. Max. 
tremor 0°4 mm. 
1 See British Association Report, 1898, pp. 180-182. 
