32 
‘Tt will be seen that the direction of the wind is well re- 
presented at all the stations, excepting Buncrana; and the 
anomaly at this station is readily accounted for by the modify- 
ing influence of Lough Swilly, and its double chain of moun- 
tains. 
“We have seen that the centre of the vortex was between 
Armagh and Markree at 9 a.m. of the 19th; and, as the 
direction of its progressive movement was not far from the 
line connecting these places, ‘it must have passed nearly cen- 
trally over both. Hence we should expect there the peculiar 
phenomena—the ull of the wind, and the sudden reversal of 
its direction—which are observed to occur at places in the 
path of the centre of a cyclone. I shall therefore briefly de- 
scribe the series of changes at these two stations, which have 
been kindly furnished in much detail by Dr. Robinson and 
Mr. Cooper. The observations at Armagh are from the re- 
cords of the self-registering anemometer, and are consequently 
continuous ; those at Markree were taken at short intervals. 
‘At Armagh the wind began to blow at 7 p.m. of the 
18th, with a velocity of 22 miles an hour. The maximum 
velocity (with the exception of that of a short squall* at 5 a.m.) 
occurred at 7 a. M. of the 19th, and amounted to 30 miles an 
hour. From this time the wind abated rapidly almost to a 
calm, its velocity at noon amounting only to 4 miles an hour ; 
and at 3 P.M. it rose again, with a velocity of 15 miles. The 
initial direction of the gale was from the E.S.E. From 9 p.m. 
on the 18th, to 1 a.m. on the 19th, it veered to S., at which 
point it continued for several hours, including the period of 
greatest force of the gale. At 11 a.m. its direction had re- 
turned to §.E., and it then suddenly shifted to W.N.W., 
altering through 160° in 24 minutes. The minimum pressure 
took place at 115 30™, at the close of this movement; its 
amount was 27°930 inches. 
* During this squall, which lasted only three minutes, the velocity reached 
60 miles an hour. 
