REYNOLDS: ERUPTION OF KRAKATOA. 
217 
lar manner, the origin of the barometric disturbance was calculated 
to occur at 9 hours 1 3 min. local time. The mean of the two values 
obtained from the one series of waves travelling against the earth's 
motion or revolution and of the other of the waves travelling with 
it, fixes the time of the origin of the disturbance at 9 hours 24 min. 
local time 27th August. The velocity of the waves travelling from 
east to west was 674 miles per hour; of those passing from west to 
east it was 706 miles. No very exact comparison with the velocity 
of sound is possible, as this varies with the temperature: at 50^ F. 
it is 757 miles per hour; at 80° it is 781 miles. The wave travelling 
from east to west was perceptible on the tracings for 122 hours after 
its origin: it travelled upwards of 82,000 miles, and had passed 3 J 
times round the entire circuit of the earth before its extinction." 
" It was, of course to be expected that the influence of this 
wave might be recognised afc Leeds. Through the kindness of Mr. 
Branson, of the firm of Messrs. Eeynolds and Branson, I have had 
the opportunity of inspecting the tracing made by one of their self- 
registering aneroids for the week comprised between August 27th 
and September 2nd. The curve, although on a smaller scale than 
those engraved on Mr. Scott's paper, is precisely similar in character 
to the barograms from Aberdeen, Stonyhurst, Glasgow, Armagh, and 
Valentia Island. The first rise at these places occurred on August 
27th, at from 1 to 1.20 p.m. ; the first fall varied from 1.25 to 1.48; 
the second rise at from 1.53 to 2.25 p.m.; the amplitude of the 
oscillation being about •05in., and its duration about an hour. 
Owing to some slight imperfection in the action of the instrument, 
due probably to the fact that the new paper for the week was introduced 
shortly before this time, the tracing is not complete for the morning 
of Monday, the 27th. The next movement, however, is well marked. 
The rise occurred at about 3 a.m., and the depression at about 3.45, 
which is almost identical with the times of the other stations; the 
amphtude was about '07 in. On the 27th there was another dis- 
turbance, shown on ths L3eds tracing to have occurred at about 
2 a.m.; the times at the other stations were 1.50 a.m. at Aberdeen, 
2 a.m. at Stonyhurst, and 2.28 a.m. at Valentia. On the same day 
there was a disturbance due to the wave, travelling from west to 
