162 REPORT—1899. 
Omori, in charge of Seismological Observatories in Japan, Mr. T. Heath, 
of the Royal Observatory, Edinburgh, and by many others directly or 
indirectly interested in the work of this Commitize. 
Il. Notes respecting Observing Stations and Registers obtained from 
the same. 
1. England : Isle of Wight, Newport, Shide. Observer, Mr. J. MILNE. 
The continuity of records obtained from this station has largely been 
dependent upon the interest shown in the work by Shinobu Hirota, Mr. ~ 
Milne’s assistant. 
At rare intervals, usually in consequence of some irregularity in the 
band of bromide paper, the clock driving the same has been stopped. 
Failures due to this cause have been extremely few. The greater number 
of failures arise from ‘air tremors,’ which during the winter months, in 
frosty weather, and at night are frequent. Slight continuous movements 
of the boom produced by these air currents have no doubt eclipsed many 
gmall earthquakes, and have certainly hidden the commencement of larger 
disturbances. These difficulties, which occur from time to time, and 
interfere with observations for at least one month out of twelve, are not 
likely to be overcome until the instrument is moved to a larger and better 
ventilated room. 
A pair of horizontal pendulums recording on smoked paper have 
given records of the periods of earth vibrations. 
The Shide Register. 
The following register is compiled from the photographic records of a 
Milne Horizontal Pendulum, and refers to E.W. displacements. The time 
used is Greenwich Mean Civil Time. Midnight=24 or 0 hours. 
Amp. = Amplitude, or half the complete range of motion. It is expressed 
in millimetres, 1 mm.=0''5 of arc. Records of -5 mm. or less refer to a 
inere thickening of the line, and indicate half its width. 
D = Duration expressed in hours, minutes and seconds. 
P.T.’s = Preliminary Tremors, the duration of which is from the first movement 
to the maximum motion. 
L.W.’s = Large waves, and refers to the maximum motion. 
Doubtful means that it is not certain that the record refers to earthquake 
morion. 
The instrument stands on 2 brick pier founded on the upended beds of 
hard chalk. 
| | 7 
| No. | Date Nereida Remarks 
1898. 
| (ae. ae Se 
| 170 | Feb. 27 |) ll 7 44 | Amp.:25mm. D 4m. 
| 171 | Mar, 3| 165 87 34 | Doubtful. 
(age es ee 4116.58 3h - 
| 175 | 4 + 21 13 46 Amp. ‘25mm. D 6m. 
A ne als 5 | 16 35 12 | Doubtful. 
| 175 loa, a di) SHG 44 22 * 
176 | x 19 4 45 29 Amp. °25mm. D 2m. 
| 177 |, 21) 22 51 50 | Thirteen small group up to 1h. 30m, on 22nd. | 
Max. about Oh. 30m. 
i478 i°j, 231 2048 G | Amp.-25mm. D 2m. 
