20 PRINCIPLES OF GARDENING. [CH. I, 



temperature, var^-ing between 21° and 31°, the soil 

 had frozen to a depth of 4 J inches, but at lower 

 depths the temperatui'es w^ere as follow : — 



At 6 mches . . 34° 



— 12 „ . . 36i 



— 24 „ . . 39 



In every instance the lighter soils were frozen 

 to a less depth than the more tenacious. The for- 

 mer in no case having the frost penetrate lower than 

 six inches, but in hesi\j soils two inches deeper.* 



The following table, kept by Mr. Shai-p, the scien- 

 tific manager of the Winchester gas works, shows 

 the lowest temperature of the air at night, and its 

 highest temperature by day during the January of 

 the present year, as well as the temperature of the 

 soil at six inches and at twelve inches below its sur- 

 face. The soil is black, rich, and siliceous, resting 

 on a chalky subsoil : — 



^ Gardeners' Chronicle. 



