APPENDIX. 419 



On comparing these results with the most accurate accounts 

 we have of the climate of the Eastern States on their first 

 settlement, we shall find that it was much the same as that of 

 the north western frontier at the present time. The winters 

 were much more severe, the summers warmer; and the mean 

 temperature of the year probably about the same that it now is. 

 Similar changes are believed to have taken place in Europe ; 

 and this fact will in a great measure account for the contra- 

 dictory statements of writers on this subject; some of whom 

 affirm that the climate of Europe and the eastern part of the 

 United States is warmer, some that it is colder; and others 

 that there is no material change. The one party stating, by 

 way of proof, that the Rhine, Danube, and Tyber rivers, the 

 Euxine and the borders of the Mediterranean Sea, &c. were 

 frozen during the winter months of former years, and that 

 many plants could not be preserved through the winter, even 

 in the north of Italy, which are now successfully cultivated in 

 much higher latitudes ; while the other asserts that at present 

 many kinds of grain and fruit will not come to perfection in 

 large districts of country, where they formerly flourished and 

 were perhaps indigenous. 



The truth probably is, that the mean annual temperature 

 is about the same ; but that the climate is much milder in conse- 

 quence of the great reduction in the range of the thermome- 

 ter — that the quantity of heat is the same ; but that it is now 

 more equally distributed throughout the year. This supposi- 

 tion will explain the facts above stated. For on comparing 

 the monthly mean temperature of the western and eastern 

 posts as given in these tables, we shall find that, although in 

 January it is much lower at the west, yet the spring advances 

 more rapidly ; that even by March it is 2° 45' higher than at 

 the eastern posts ; and that by July the difference is 6° 49'. 

 Of course, such plants will thrive as require a warm summer 

 to bring them to perfection ; and are yet hardy enough, with 

 due care and a proper exposure, to withstand a severe winter ; 

 while the more delicate and sensible ones, which flourish un- 



