226 BOARD OF AGRICULTURE. 



■water becomes so warm as to be converted into vapor it acquires 

 a vastly increased capacity for storing away latent heat which 

 it absorbs from all surrounding objects. For this reason the 

 hands of the washer-woman wet with warm water freeze so 

 quickly while hanging out her clothes, and for the same reason 

 the low wet places suffer from the first frosts of autumn. We 

 have noticed the crops on wet lands injured by the frosts of 

 September, while near by on well drained land they escaped all 

 damage. 



On the wet places also the fogs make their first appearance 

 and continue the longest. However transparent the air it 

 always contains aqueous vapor, and the higher the temperature 

 of the air the greater the amount of vapor it is capable of con- 

 taining. When the air comes in contact with any body 40° 

 colder than itself its capacity for retaining the moisture is so re- 

 duced, that the vapor becomes instantly visible. Thus the mois- 

 ture of our breath is* instantly turned into vapor, as it leaves 

 our mouths of a cold winter's morning, and the vapor of a lo- 

 comotive in a cold day makes a beautiful cloud which lingers 

 long after the train has departed. For the same reason when 

 the air comes in contact with cold moist land, the vapor which 

 before was latent becomes visible and causes the dismal, shiver- 

 ing fog. This nebulous appearance when examined by a mi- 

 croscope or illumined by the sun with a dark back ground is 

 found to be composed of an infinity of minute watery vesicles. 

 They group themselves in the form of spherules and obey the 

 law of gravitation, being densest near the surface of the earth. 

 Fogs are often seen on a river in a cold winter morning, when 

 the water of the river being warmer than the air, the vapor 

 rising becomes visible. When the land is naturally dry and 

 porous or is made so by drainage fogs seldom intercept the sun's 

 rays and make the air damp and chilly. The warm air pene- 

 trates such a soil, giving life and breath to the plants and the 

 climate is equally healthy, for man and beast. The porous na- 

 ture of some of our Western prairies especially in Kansas, 

 makes the air delightfully clear and dry. After a rain the land 

 becomes speedily dry and the air pure. We recently asked an 

 aged but hale-looking friend how long he had lived in Kansas. 

 Ten years was his reply, and I am ten years younger than when 

 I came here. We cannot hope to make our soil as deep and 



