Knowledge of the Ancientsr 265 
any inferior degree: a fact worthy to be afcer- 
tained by experiment. 
II. I believe the faft, Of the produftion of cold 
by the evaporation of fluids, is efteemed a modern 
difeovery, as it juftly may be: but it (till ap¬ 
pears (though the modern difeoverers were not 
acquainted with it) that it was familiarly known 
to the ancients, and not only to the Greeks and 
Romans, but the Egyptians alfo. 
Athenasus mentions, “ that Protagorides, in 
deferibing the navigation of Antiochus upon 
the Nile, or Euphrates, relates the method ufed 
in that country, of cooling liquor, which was, by 
firft heating it by expofure to the fun, and then 
draining it, and fetting it in earthen jars in the 
higheft, and mofl: open and expofed part of the 
building, whilft two boys were employed all the 
night, in keeping the outfides of the jars moift. 
After this, they preferved the coolnefs of its 
temperature, by covering the jars with draw. 
This, fays he, cooled the water to fo great 
a degree, that they felt no want of ice.” * 
Galen fays, the method of cooling water, ufed at 
Alexandria, was as follows : “ About fun-fet, they 
poured water which had been firfl: heated, into jars, 
which theyhungupinthe higheftpartsofthebuild- 
ings, with the windows open, oppofite to that point 
from whence the wind blew. Before fun rife, they 
* Athen. p. 124. 
placed 
