316 THE INDIAN SUMMEE. 



three days resembling it after the first cool weather of 

 October, and these short visits are in some years repeated 

 several times. But a true Indian Summer, attended with 

 all the peculiar phenomena described by some of our 

 early writers both in prose and verse, rarely accompanies 

 a modern autumn. It has fled from our land before the 

 progress of civilization ; it has departed with the primi- 

 tive forest. I will, however, for the present, set aside all 

 my conjectures of its mythical character, and treat it as a 

 matter of fact. 



The Indian Summer, if such a season was ever known, 

 was a phenomenon produced by some unexplained cir- 

 cumstances attending the universal wooded state of the 

 country that existed for many years after its settlement. 

 According to the most apparently authentic accounts, it 

 did not arrive until November, nor untO. a series of hard 

 frosts had destroyed all the leaves of the forest. It then 

 appeared regularly every year. At the present time peo- 

 ple know so little about it that they cannot name the 

 period of the autumn when, if it were not a thing of the 

 past, it should be expected. "Will the disappearance of 

 this phenomenon admit of a philosophic explanation ? 

 Let us consider some of its probable causes, and the 

 effects of the changes which have taken place in our 

 land. 



It has been observed that a meadow covered with lux- 

 uriant grass and other herbage cools the atmosphere that 

 rests upon it much more rapidly than a similar meadow 

 covered with a scanty herbage. The moisture exhaled into 

 the air by vegetable perspiration is greater than from any 

 other natural surface; and as the radiation of heat is 

 rapid in proportion to the moist condition of the atmos- 

 phere, the cooling process over a grassy meadow is vastly 

 greater than over a similar ground bare of vegetation. A 

 wood, in like manner, by exhaling through its foliage the 



