REPORT—1899. 
Slight disturbance at Gh. 55m., being a wave period 20m., 
amp. 23’. 
15 Me 2 33 Conspicuous isolated disturbance at from 6h. 30m. to 
7h. 30m., being an oscillation with amp. =113’. 
76 | Nov. 1 2. 68 | No disturbance. 
1897. 
77 | Jan. 10. 18 58 Very minute oscillations, amp. under 2’, commencing 
14h. 8m., continued for 5 hours, then at 19h. 40m. a 
slightly larger oscillation occurs, amp. 23’, followed by 
another of same amp., but opposite phase. 
78 | Junel2 . 9 9 | No disturbance. 
79 | Aug. 4.| 22 2 | Very slight oscillations of small amp. about 2’, and long 
period, commencing at 14h.50m. Hardly to be called a 
disturbance. 
80 | Sept. 20. 17 4 | No disturbance. 
81 pieeka 3 8 | No disturbance. 
82 | Dec.28.| 18 34 
83 he ce 9 20 
VIII. Form of Reports. 
It is desirable that Reports on Earthquakes should contain the follow- 
ing information :— 
1. Greenwich Mean Civil Time (midnight = 0 or 24 hrs.) of the com-_ 
mencement of motion. 
2. The duration of the first preliminary tremors (P.T.’s) usually repre- 
sented by a broadening of the normal line. 
3. The interval between the commencement of motion and the maxi- 
mum motion. 
4. The interval between the maximum and its apparent repetition, 
which, when it occurs, does so a few minutes later. This is the interval 
1 to 1’ seen in fig. 3, p. 229. 
5. The amplitude or half-range of the maximum motion expressed in 
millimetres and seconds of are. 
6. The total duration of the disturbance. 
7. For large earthquakes a contact print, or at least a tracing of 
the disturbance, may be appended. 
8. The time, duration, and amplitude of isolated broadenings of the 
normal trace. These must not be confounded with air tremors. 
For the ordinary working of the instrument, see ‘ Brit. Assoc. Report,” 
1897, p. 137. 
Photographic Meteorology.—Report of the Committee, consisting of 
Mr. G. J. Symons (Chairman), Mr. A. W, CLAYDEN (Secretary), 
Professor R. Mreupota, Mr. Jonn Hopkinson, and Mr. H. N. 
Dickson, appointed to apply Photography to the Elucidation of 
Meteorological Phenomena. (Drawn up by the Secretary.) 
Tur work of the Committee has for some years past been practically 
limited to the photographic measurements of cloud altitudes by the Sec- 
retary. During the year just brought to a close very little progress has 
