519 



probable that evidence bearing upon it may be obtained. 1 

 shall only observe that, in seeking and comparing such evi- 

 dence, care must be taken not to confound eddies arising from 

 local obstructions with the general direction of the current. 



" The hours of observation at the Magnetical Observatory 

 are 7 a.m., 10, I p.m., 4, 7, 10. The observations of the 

 barometer, and of the dry and wet thermometers, made at these 

 hours on the day of the storm, are the following : — 



The fall of rain and melted hail in 'I'rinity College during the 

 storm amounted to 0*596 of an inch ; but it is probable that 

 the hail was driven out of the receiver of the gauge by the 

 wind. 



" It will be seen that the barometric fluctuation is small. 

 It is stated, however, that a sudden and considerable fall of 

 the barometer took place shortly before the storm. From the 

 observations above given, at 1 and 4, p. m., it will be seen 

 that the barometric equilibrium, if so disturbed, was soon 

 restored. 



" I have collected from the newspapers and other sources 

 such information as I could obtain respecting the area of the 

 city visited by the gale, but it is as yet incomplete. It appears, 

 however, that the diameter of the vortex was not very different 

 from the length of the city from north to south ; the gale having 

 been limited by the Circular-road in these two directions. 

 Hail fell, however, abundantly beyond the limits of the gale. 

 Thus, at the gardens of the Royal Dublin Society, at Glas- 

 nevin, the damage done by the hail was very great ; but it 



VOL. IV. 2 Q 



