EVAPORATION. 277 



perse. If in some places the sky continued clear during 

 the eclipse, the atmosphere in those places probably con- 

 tained less moisture than those before mentioned, and 

 was therefore able even at a diminished temperature to 

 support it in an invisible state. In the town, in which 

 the writer of this resides, it was observed that on and 

 near a certain pond, it snowed constantly during the 

 latter part of the eclipse, while at a distance from the 

 pond no snow fell. In this case it would seem that the 

 atmosphere over the pond was saturated with moisture, 

 and that as the air over land cools more rapidly than that 

 over water, the colder air from the land moved towards 

 the pond and produced the condensation of vapor and the 

 consequent formation of snow which was noticed. 



Perhaps there is scarcely any operation of nature, which 

 more strikingly displays the wisdom and goodness of God, 

 than evaporation. Let this cease, and the earth would 

 become a desolate waste, except where the laborious ef- 

 forts of man might, by frequent watering, create a spot of 

 verdure here and there, amid the desert. The important 

 effects resulting from so simple a cause may well lead us 

 to admire the wisdom and goodness of that Being who is 

 ' wise in counsel, and wonderful in working,' and who 

 ' maketh the sun to rise on the evil and the good, and 

 sendeth rain on the just and on the unjust.' 



The facts mentioned in the foregoing pages show that 

 the subject of evaporation, especially when considered in 

 connexion with changes of the weather and with meteor- 

 ology in general, opens a wide and interesting field for 

 reflection and investigation. And this field is open to all. 

 Here he who will may study the operations of nature, and 

 search for the principles by which those operations are 

 guided and on which they are conducted. 



To the reflecting mind it is ever a source of pleasure 

 to be able to trace effects up to causes, and to ascertain 

 the various relations which subsist among the works of 

 nature. Indeed, who would not prefer the knowledge of a 

 Franklin who could trace the lightning's path and guide 

 it to the ground, to that of him who thinks there will be a 

 thunder-shower to-day because the clouds look as they did 

 last year before a thunder-shower, but who knows nothing 



