J826 M. Arago on the Thermometrical State 



dicate the temperature of Jerusalem to be» 70% or somewhat 

 more. 



M. Leopold de Buch places the southern limit of the vine in 

 the island of Ferro, one of the Canaries, the mean temperature 

 of which must be between 69°.8' and 71°.6' Fahr. 



At Cairo and its neighbourhood, with a mean temperature of 

 71°.6,' we find here and there some vines cultivated in the gardens, 

 but no vineyards properly so called. 



At Busheir, in Persia, whose mean temperature does not cer- 

 tainly exceed 7S°.4,' it is impossible, according to Niebuhr, to cul- 

 tivate the vine except in dry ditches, or in shady places out of 

 the direct influence of the sun. 



But we have seen that in Palestine, in the remotest times, 

 the vine was, on the contrary, generally and largely cultivated, 

 so that it is necessary to admit that the mean temperature of 

 this country does not go beyond 71°.6. And the cultivation of 

 the palm has just taught us, that we must not allow for this 

 same temperature a number under 69°.8. And thus the simple 

 phenomena of vegetation lead us to characterize, by a tempera- 

 ture of 71°, the climate of Palestine at the time of Moses, and 

 it appears that any error can scarcely extend to an entire de- 

 gree. 



And what is the mean temperature of Palestine at the pre- 

 sent day.? Unfortunately, direct observations are awanting; 

 but we can supply them by terms of comparison taken from 

 Egypt. 



The mean temperature of Cairo is 71°.6 ; Jerusalem lies 2° 

 more to the north. Two degrees of latitude correspond, in these 

 climates, to betwixt a degree and a degree and a half of Fahren- 

 heifs scale. The mean temperature of Jerusalem then ought 

 to be a little above 69°.8. For the more remote times, then, we 

 find the two extremes 69°.8' and 71°.6', and for the mean 70°.8'. 



All, then, leads to the conclusion that the chmate of Palestine 

 has not changed to any appreciable extent in the course of 3300 

 years. 



The invariability of this particular climate may also be inferred, 

 though with less certainty, from many other agricultural facts. 



The culture of wheat, for example, would prove that the 

 mean temperature does not exceed 75".^' or 77°. The balsam 



