240 NINTH ANNUAL REPORT OF 



No. 3.— THE SEA BREEZE. 



The tables contained in my last number exhibit the great excess of 

 sea winds over land winds in every month of" the year 185], excepting 

 January, when the excess was in favor of land winds- In this respect, 

 the month of January in the present year corresponds with the last. 

 December, 1850, shows a very slight preponderance of land winds. 

 From these data I infer the general rule, that the westerly or sea winds 

 predominate in every month except January and December, and that 

 the latter month varies in this respect, behig sometimes on the one side 

 and sometimes on the other. 



I have already stated that the westerly winds increase, both in fre- 

 quency and in force, from February to July, and then begin to fall off 

 very gradually. The precise relation of sea to land winds, in each 

 month, as to frequency, is shown by computing their per centage of the 

 whole number of observations. The result tor the year 1851 is as fol- 

 lows : 



January, sea winds 44 per cent. 



February, do 63 do. 



March, do 81 do. 



April, do » 86 do. 



May, do 95 do. 



June, do 96 do. 



July, do 97 do. 



August, do 97 do. 



September, do 96 do. 



October, do 78 do. 



November, do 73 do. 



December, do 38 do. 



To which may be added — 



December, 1850, sea breeze ~. 49 do. 



January, 1852, do 34 do. 



Februa"ry, 1852, do 69 do. 



Whatever may be the direction of the wind in the tbrenoon, in the 

 spring, summer, and autumn months, it almost invariably works round 

 towards the west in the afternoon. So constant is this phenomenon, 

 that in the seven months from April to October, inclusive, there were 

 but three days on which it missed, namely, on the 8th of April, the 18th 

 of Ma3S and the 27th of August. And these three days were all rainy, 

 with the wind from the south or south-southwest. 



The sea winds arc moderate in the spring until the month of May, 

 when they begin to give trouble. In June they increase in force, reach- 

 ins; their greatest violence about the beginning of July. In August they 

 begin to decline in force, though not in constancy. In September they 

 continue steady, though moderate; and in October they lose their an- 

 noying qualities, and become gentle and agreeable. 



The sea winds of summer are commonly supposed to come from the 

 northwest. But this is a great error, arising, no doubt, trom the fact 

 that our citizens have mostly been accustomed to cold winds, in th^ 



