io ROUND THE YEAR 



suffered most from frost, in order that his friends may 

 learn to plant only such as can stand severe cold. 

 This is of a piece with his constant interest in house- 

 hold matters, the making of rushlights, the small, long, 

 shining fly which lays its eggs in bacon, the holes 

 gnawed by crickets in stockings and aprons hung to 

 the fire, and the like. 



White foretold one of the chief applications of 

 Zoology to the practical affairs of mankind in the 

 following passage : " A full history of noxious insects 

 hurtful in the field, suggesting all the known and 

 likely means of destroying them, would be a most 

 useful and important work. A knowledge of the 

 properties, economy, propagation, and in short of the 

 life and conversation of these animals, is a necessary 

 step to lead us to some method of preventing their 

 depredations." 



A little elementary Physics, so cheap nowadays, 

 would have greatly mended some of White's explana- 

 tions. He thinks that thaws often originate under 

 ground, from warm vapours that arise. He remarks 

 truly enough that " when a thermometer hangs abroad 

 in a frosty night, the intervention of a cloud shall 

 immediately raise the mercury ten degrees ; and a 

 clear sky shall again compel it to descend to its former 

 gauge." But this leads him to conclude that "cold often 

 seems to descend from above." Nor could he interpret 

 his own observation of unusual cold in low-lying and 

 sheltered spots. It is easy now to point out that in 

 perfectly still weather the air which is chilled, and 

 therefore of greater density, will collect in hollows. 

 Promising boys in an elementary school are taught 



