CLIMATE OF AMERICA. 151 



unconscious of all things; they have only to do with our 

 summers. 



The temperature of the air, and the general state of 

 the atmosphere, as I have elsewhere stated, have a pow- 

 erful effect on the filature and the spinning of silk; both 

 are favorable in Piedmont. Italy is renowned for its 

 delightful climate and serene atmosphere. I will now 

 attempt to shew that our own climate, during summer, 

 is more favorable to the silk- worm than that of Europe, 

 in the proportion of two to one. The average heat of 

 our midsummer months must be nearly equal to that of 

 Rome, in Italy, and of Marseilles, in the south of France ; 

 since the mean of the greatest heat at Cambridge, which 

 is in lat. 42 deg. 23 min., exceeds that of Rome by 11 

 deg., and that of Marseilles by 8 deg. The mean of our 

 greatest summer heat being 97 deg. and seldom a sum- 

 mer passes that the thermometer does not rise to 100 

 deg. or more. 



From the average of the observations which have 

 been made in twenty cities on the continent of Europe, 

 I shall compare the climate of America. 



While the quantity of rain which annually falls in the 

 twenty cities of Europe is but thirty inches, with us it is 

 fifty inches : yet in Europe, while it rains annually 122 

 days, we have but eighty-five or ninety days of rain ; the 

 rain with us descending, not in slow and perpetual show- 

 ers, but more often in profuse showers and in torrents. 

 Yet while in the twenty cities of Europe the number of 

 fair days or days of sunshine is but sixty-four in the year, 

 in America we have annually 130 bright days, or days 

 of sunshine, or a double number which they have in 

 Europe. Thus it evidently appears that during sum- 

 mer, the climate of the finest countries of Europe can 

 by no means compare with ours with our skies so se- 

 rene, our atmosphere so unclouded, with our days of 

 brilliant light and more perpetual sunshine. During the 

 cold days which may sometimes occur, there is always 

 the easy remedy ; but in excessive and long continued 



