THE SMITHSONIAN INSTITUTION. 249 



but, after all, the weather is not so misty as might be supposed. By 

 referring to the table given in my last paper, the misty weather appears 

 to havebeen distributed as follows, in the fQur seasons of the year: 



Winter 13 mornings, 5 afternoons, 7 evenings. 



Spring 9 do. 3 do. 4 do. 



Summer 1 do. 11 do. 34 do. 



Autumn 6 do. 4 do. 9 do. 



It should be noticed that the mornings were seldom misty for more 

 than an hour or two after sunrise, and the afternoons not often misty 

 throughout. The mist generally comes in detached clouds, driven by 

 the wind, and sometimes in a universal stratum. Nearly alwa3^s it 

 gravitates sensibly towards the earth, in the form of a very fine rain, 

 occasionally wetting the surface. 



In the entire year there was mist on 27 mornings, 21 afternoons, and 

 45 evenings. At Philadelphia the average is about 20 mornings, 5 af- 

 ternoons, and 10 evenings. 



The tendency to the production of mist reaches its height in July. 

 There were 19 foggy evenings in that month. The winter months, 

 however, were most productive of mist in the morning. In the summer 

 months there was but one foggy morning. 



I now come to speak of the direction of the wind and clouds during 

 the rains. In the sixteen months ending with March, 1852, and conse- 

 quently embracing the greater part of two rainy seasons, there were 79 

 days on which rain fell, with the wind as follows: 



East 0, northeast 2, north 2, northwest 6, west 8, southwest ]7, south 

 20, southeast 24. 



Or, the classification may stand thus : 



East and northeast 2 



North and northwest 8 



West and southwest - 25 



South and southeast 44 



Thus, from east and northeast, emphatically the rainy quarter in the 

 Atlantic States, there was scarcely any rain. More than half the rains 

 came from south and southeast. The rainiest point is in a direct line 

 with the southern coast, or about south-soulheast. 



The easterly storms, which form so prominent a feature of the Atlan- 

 tic climate, are unknown here. There is nothing that bears a resem- 

 blance to them. The rains from southeast are often attended by high 

 gales, whi("h extend over a large portion of the western coast of North 

 America, and inflict some injury on shipping. But these gales are less 

 violent than the most severe easterly storms of the Atlantic coast. 



The direction of the cloud producing the rain is often of greater im- 

 portance than that of the lower atmospheric current. There are mostly 

 two strata of clouds, the lower concurring with the wind on the earth's 

 surface, and seldom supplying rain, and the higher, which is the true 

 rain-cloud, varying in its course from the lower, and sometimes having 

 the very opposite direction. 



