294 



It is a circumstance deserving of notice, that the direction 

 of the wind continued nearly unchanged during the whole 

 period of the transit. The wind was from between W. and 

 SW. at the commencement, and continued between the 

 same points (with a very brief interruption on Feb. 1) until 

 the passage of the crest of the wave, when it shifted tempo- 

 rarily to the NW. (Feb. II, 12); it then returned to W. 

 and SW,, and so continued during the remainder of the pas- 

 sage. There was a high gale before the commencement of 

 the transit (Jan. 22-26); and another (Feb. 19, 21, 22) 

 after its completion. The wind was also high, February 

 7-10, reaching its maximum February 9, shortly after the 

 passage of the trough dividing the two portions of the wave. 

 During the passage of the crest it was calm. 



The barometer never attained so great a height since the 

 regular series of meteorological observations commenced (ten 

 years ago) at the Magnetical Observatory. In order to ascer- 

 tain whether so great a pressure had been observed at an earlier 

 period. Dr. Lloyd consulted the long and regular series of 

 observations kept by the late Dr. Orpen, and presented by 

 him to the Academy. It appeared from this examination that, 

 within the last forty-five years, the barometer only once at- 

 tained an equal height. This took place in January, 1825. It 

 may not be uninteresting to meteorologists, with a view to the 

 questions above referred to, to possess a record of the epochs 

 of the occurrence of the greater barometric oscillations, as ob- 

 served at Dublin. Accordingly the following Table has been 

 prepared, giving the list of days from 1805 to 1848, inclusive, on 

 which the mean daily height of the barometer exceeded 30*50 

 inches, together with the observed maxima. The observations 

 from 1805 to 1838, inclusive (taken from Dr. Orpen's register), 

 are uncorrected. 



