ON SEISMOLOGICAL INVESTIGATION. 181 
be considered : the variation in the scale value of the instrument. As 
the boom points to the north, an increased sensibility means that the 
boom pillar has tilted towards the south, and vice versd. 
In the following table will be found the smoothed scale values for 
every four days from 1898, October, to 1899, January. (A bar represents 
an adjustment.) 
Value of 1 Mill. 
Day October November December January 
4 33 38 25 32 
8 32 50 ry) 41 
12 31 45 38° 50 
16 30 36 33 58 | 
20 25 28 Ba 33 | 
24 18 26 28 33 
28 54 25 24 33 
32 46 | 25 21 33 
If the above figures are plotted down on acurve, after allowing for the 
alterations for adjustment, it will be seen that the boom tilted towards 
the south till November 25 ; was then practically stationary till the 
middle of December, after which the tilting continued towards the south 
till the end of the month, when a northerly tilt set in, lasting till 
January 16, after which the boom was stationary. 
Mauritius Register. 
No. eo Date | Commence- Maximum Remarks 
0. ment 
1898. 
H. M. S. H. M. S. A. 
1}; — Sept. 19 — 1L 139 | 2/4. Commencement 1h. 
earlier ? 
2 | 233 se 2D, -— 13 50 25 =| 0'45. 
3 | 238 Oct. 15 4 612 410 0 | 0'"15. D 22m. 
4 | 239 Nov. 17 13 45 23 14 2 O | 0O'°66. D 40m. 
5 | 240? Dec. 1 _— 0 58 43 | Karthquake? 
6 | 244? ee 7 oOo @ 52. 'O |'0"-12.— D'4bm, 
About 
7 — Abii 7 O30 7 362-5 0-38. D lh. 22m. (See 
Register for Toronto, Vic- 
| toria, Nicolaiew.) 
1399. 
8 | 250 Jan. 25 — I 15) 45: 3 |-0"-99% 
and 
9° — I — Oa O From 6.30 to noon, about 
20small disturbances. One 
about 9h. looks seismic. 
10 | 263 March 6 _ 23 20 O | Slight thickenings of the 
to March 7 line. 
1 Bi (0) 
11 | 264 a le _ 8 20 0 | Slight thickenings of the 
to line. 
10 50 O 
