Magnetism and the Trade Winds. 283 



Farm situated twenty-five miles above Nashville; surface undulat- 

 ing, abounding in limestone. Hemp and corn do well, tobacco also ; 

 wheat and cotton inferior ; grapes tolerable. 



From Thomas MeauXy Amelia county, Virginia, 

 Lat. 37° 20' N. ; Long, 78° W. 



Point of observation about thirty miles WSW. from Richmond. 



Prevalent winds in spring, summer, and autumn, from SW., rain 

 falling in showers during these seasons. Gusts and tornadoes, with 

 black clouds, come from NW. in late summer ; protracted rains in 

 spring and fall come from NE. 



Prevalent winds in winter E. to W. northwardly. Kains and 

 snows in winter from NE. Lowest observed temperature 6° Fahr., 

 at sunrise, January 29, 1844; highest 97°, noon, in shade, 20th 

 July 1844. 



These observations made for twenty years. 



From Willis Fawcett, St Charles, Missouri. 

 Lat. 39° N. ; Long. 90° 30' W. 



Wind from any point of the eastern half of the horizon will bring 

 rain generally, after blowing twelve hours. It frequently happens 

 that we have winds in a dry time to blow much longer, even several 

 days, from that direction, without rain ; but on the wind's shifting 

 to the opposite side, we are sure of rain. I think our rains during 

 summer come most frequently from the SE. Wind from the SW. is 

 generally accompanied by good dry weather ; W. and NW. are dry. 

 I have noticed that thunder and lightning in the N. is almost inva- 

 riably followed here by storms of rain and hard wind within twelve 

 or twenty-four hours. 



My farm is on an alluvial prairie plain (probably formed by the 

 washings of the Missouri and Mississippi), six miles below St 

 Charles. 



The apple is our main dependence. Peaches also flourish finely ; 

 as do plums, cherries (except the black), strawberries, gooseberries, 

 wild and cultivated. Wheat and corn are the principal productions. 

 Timothy hay will soon be exported from our neighbourhood to a con- 

 siderable extent. I cultivate wheat and corn almost exclusively. 



Thus shewing, as far as this evidence goes, that the SW. 

 winds — the winds suggested by the charts — are, except in 

 Western Missouri, the rainy winds. These winds, like those 

 between the same parallels upon the ocean, are going from 

 a higher to a cooler temperature ; and these winds, in the 

 Mississippi valley, not being in contact with the ocean, or 

 with any other evaporating surface to supply them with 



