MARCH. 



iir 



ground to a considerable depth is warmer, by many degrees, 

 where the rain is drained off, instead of being allowed to 

 accumulate and evaporate. Hence this enormous loss of an 

 invaluable stimulus to vegetation. 



This chilling and deadly process of evaporation is going on 

 to excess from the time frost comes out of the ground in the 

 spring, till freezing again occurs. At this period, the mi- 

 drained land, having the most water to freeze, becomes the 

 warmest, say in December, when of no value to vegetation, 

 but rather an injury. For once, forsooth, the undrained land 

 is warmer than the drained ! But for this excess of heat in 

 winter, this kind of land must pay dearly in early spring. 

 How is all this ? inquires the farmer. Simply because water, 

 in congealing to either ice or snow, has its capacity for heat 

 lessened about one ninth, and this excess is given off to sur- 

 rounding bodies ; or, in other words, its latent heat is set free. 

 On the other hand, ice, or frost as it is called in the ground, 

 in melting, demands back this same heat, at the rate of from 

 one eighth to one ninth of 1000°, for every pound melted ; 

 and under the surface it does not obtain all this directly from 

 the sun, but through the soil : therefore the more water, the 

 colder and longer cold will be the land in the spring. Now 

 let the agriculturist go to work and make this "cold, wet, 

 heavy land" of his, the very best he has for any product, 

 trees, vegetables, grains, or grasses. 



ILLUSIVE DISTANCES AND MAGNITUDES. 



BY WILSON FLAGG. 



Every one must have observed, in the course of his own 

 peregrinations, how tiresome it is to walk over a straight and 

 level road, leading through a monotonous landscape. The 

 objects beheld in the distance ahead seem nearer than they 

 really are, and constantly disappoint us by the length of time 

 that elapses before we arrive at them. Apparent distance is 

 greatly lessened when, as in a straight road, we cannot take 



