DISTRIBUTION OF RAINS. 145 



than it was before, and this chill has produced condensation, and 

 hence a slight precipitation of mist. You may give a second 

 stroke, and the same thing will occur again. I have, during the 

 past season, h^d occasion to perform the experiment a number of 

 times, and always with the same result. 



As regards the variable quantity of rain that falls in different 

 parts of New England, in the same storm, I wish to say a few 

 words. From the modifying conditions that have been presented, 

 viz : the cflFcct of mountains, proximity' to the coast, elevation and 

 other circumstances, the quantity of rain that falls in different 

 portions of our own State, or of New England, during the same 

 storm, may be very diflerent. I have in my hand a letter from 

 James B. Francis, Esq., an eminent engineer of Lowell, Mass., in- 

 quiring as to the quantity of rain at the College in Orono, during 

 the storm ending the 4th of October, and furnishing the quantity 

 of rainfall at a number of diflFerent places in three, at least, of the 

 New England States. During that storm, there fell at Providence, 

 R. I., .83 of an inch; at Boston, 1.16; at Lake Cochituate, 4 

 inches; at Cambridge Observatory, 1.58; at Waltham, 1.56; at 

 Lowell, 2.84 at one locality, and 3.02 at another; at Fitchburg, 

 7.53; at Worcester Lunatic Hospital, 4.15, and something more 

 — the gauge overflowed ; at Amherst College, 5.83, and there, too, 

 the gauge overflowed; at Chicopee, Mass., 8.71; at Springfield 

 Armory, 8.05 ; at Springfield, 7.50 ; at Wier's Landing, Lake 

 Winnipissaukee, N. H., 6.40 ; at Lake Molage, 6.67 ; at Hartford, 

 Conn. ,8.48 ; at Orono, Maine, 2.13. 



Mr. Williams. I formerly lived in Franklin county, which is 

 mountainous, and I noticed a great many times that sudden 

 showers rising among the mountains, would usually follow the 

 river down. Perhaps it is easy to give the reason. 



Prof. Fernald. During the warm part of the year, water sur- 

 faces do not become so highly heated as land surfaces, and over 

 that portion of the earth where there is water, the temperature of 

 the air is consequently lower than over the surrounding portions 

 where there is no water. Now, where will the chill of condensa- 

 tion take place ? If there are vapor-bearing clouds passing over 

 the entire region, condensation will take place where the cool belt 

 is, and that cool belt is over tlie water. In winter the reverse 

 would be true ; but during the warm months of the year, water 

 gives rise to a cooler stratum of air than is found on either side 

 10 . . 



