in the Temperature of Winter, 13 



calls it also " tristem hiemem ;" and it was followed by 

 terrible pestilence. Nothing can be more clear, than 

 that such a winter was an extraordinary occurrence. 

 Without considering it in this light, the word " insig- 

 nis" has no meaning ; and instead of proving the usual 

 temperature of winter at Rome to have been severe, it 

 is the strongest evidence to prove that the winters were 

 generally mild, and the Tiber navigable in the winter 

 months. Had this been a common winter, or any thing 

 like it, it would not have been singled out by the histo- 

 rian as a subject of remark. This explanation is ap- 

 plicable to all the instances of cold winters, described 

 by historians. Even the passage in Juvenal, if it proves 

 any thing, confirms the opinion that the frost, in his 

 days, was not ordinarily very severe. The circum- 

 stance of a woman's breaking the ice in the morning to 

 bathe in the Tiber, indicates that the ice was usually 

 thin and easily broken ; and by no means admits the 

 supposition of ice a foot thick, like that which covers 

 our rivers. It supposes a thickness of ice which is often 

 seen on the Tiber at this day, frozen in the night, and 

 dissolved the next day. 



All the Roman writers speak of severe winters by 

 way of distinction. Virgil says, " sin duram metues 

 hiemem" — if you apprehend a hard winter. And Hor- 

 ace attempts to dissuade Augustus from his design of 

 resigning the empire, by describing the severe cold, 

 snow and hail of the winter, which he represents as pro- 

 digies, and evidences of the resentment of the gods. 

 The winter to which he refers was probably of unusual 

 severity. I apprehend the great source of error on this 

 subject has been, that the moderns have taken for rep- 

 resentations of ordinary winters, those which were intend- 

 ed for a few rare occurrences. Certain it is that the 

 common winters of Italy were not severe, but mild. 

 This I will demonstrate by a series of evidence, drawn 

 from the phenomena of the natural world, which cannot 

 deceive us in regard to climate. 



Pliny, in his Natural History, lib. 2. 47. has given 

 us an account of the winds in Italy. Among other things 

 he informs us directly that the " spring opens the naviga- 



