184 M‘Sweeny, on the Climate of Ireland. 
the north sides of the hills are chosen for its cultivation. The mean temperature of 
Algiers is 21° centigrade. In Egypt, the cultivation of the vine is insignificant ; 
Cairo has a mean temperature of 22° centigrade. At Abusheer, in Persia, they are 
obliged to plant vines in ditches, to protect them from the heat of the sun. 
From the successful cultivation of the date and vine in Palestine, its mean tem- 
perature could not have been above 22,, probably not above 21° centigrade, and he 
concludes—“ if there has been any difference between the mean temperature of Jeru- 
salem, in ancient and modern times, it can hardly amount to one degree.” 
The time of harvest formerly in Palestine, compared with the time of harvest de- 
scribed by modern travellers, he shows, favours the same conclusions. 
It follows from the observations of Theophrastus and Pliny, that as the olive tree 
was cultivated in Upper Egypt, the climate could not have been more warm, because 
the olive tree does not bear a great heat. Professor Schow thinks from comparing 
the accounts of the ancients with these of the French observers, that the rise of the 
Nile happens at the same period of the year as formerly, showing that the rainy sea- 
son began in the tropical part of Africa at the same period that it does now. 
The ancients spoke of the central part of Africa, as unimhabitable on account of 
the heat, but not from their own observation it is to be remarked. 5 
From the careful study of the writings of the ancients, and from observation of 
the vegetation of Italy at the present day, he is against the idea of any change of 
consequence having taken place in the climate of Italy. He says that the passages of 
Virgil are taken from his description of pastoral life suited to the mountains, since 
in the lower plains, there is not sufficient grass on account of the heat. Myrtle 
and bay have grown near Rome since the earliest times ; myrtle branches were made 
use of in the peace between the Romans and Sabines; and bay crowns were used in 
the time of their kings; he says that the climate could not be much colder, since 
myrtle and bay grew there. 
That the climate of the south of Europe has not been more warm, is proved by 
the account which Theophrastus gives about the date tree in Persia, which, when 
brought to Greece, did not ripen the fruit. Schow carefully compares the times of 
the corn, and wine harvests, in ancient and modern times, and thinks that the climate 
of Greece and Italy, like that of Palestine and Egypt, has undergone no important 
change ; but if on account of somewhat later harvests, and the possible growth of 
beech trees in the Roman plains, we might be led to the opinion, that formerly the 
climate had been a little colder than at present, the difference will hardly come up to 
one or two degrees, and will not be greater than might be occasioned by the im- 
provement and cultivation of the north of Europe in modern times. 
From Greece and Italy he passes to the countries on the Black and Caspian sea, 
here it has been pretended that the change of climate has been extraordinary. The 
Abbé Mann, who collected the accounts of the ancient writers, says that they concur 
