THE EXPERIMENT 193 



ble, or in some sort aerial, that is to say resembling 

 the air ; and the reduction of water to this new state 

 is called evaporation. The moisture of the linen 

 \\c wish to dry evaporates; the water is dissipated 

 in the air and thus becomes invisible vapor, which 

 spreads in every direction at the will of the wind. 

 The warmer it is, the quicker and more abundant 

 the evaporation. Have you not noticed that a wet 

 handkerchief dries very quickly in a hot sun, and 

 loses its moisture only very slowly if the weather is 

 cloudy and cold?" 



"Mother Ambroisine is always very glad when she 

 has a fine day for her washing," Claire remarked. 



"Remember, too, what happens after watering the 

 garden. When, at close of a very warm day, we 

 have to give a drink to those poor plants dying of 

 thirst, something like this happens : The pump runs 

 at its utmost capacity ; you all make haste with your 

 watering-pots; one goes here, another there, cany 

 ing water to the suffering plants, seed-plots, and 

 potted flowers. Soon the garden has drunk copi- 

 ously. How fresh it is then, how the plants, wilted 

 1)\ the heat, regain vigor and straighten up again, 

 as happy as ever! You could almost think you 

 heard them whispering to one another and telling 

 how glad they were to be watered. If it could only 

 stay that way! But, bah! the next day the earth is 

 dry once more and all has to be done over again. 

 What has become of the last evening's water? It 

 has evaporated, dissolved into the air; and now it 

 is perhaps traveling far away, at a great height, 

 until, turned into a scrap of cloud, it falls again in 



