wind, Thrascias and Gallicus. From the northern side 
of Aquilo, the north-east wind, blows Supernas, from its 
southern side Boreas. Solanus, the east wind, has Car¬ 
bas on its northern side, and Ornithiæ on its southern 
side. Eurus, the south-east wind, has Cæcias and Vul¬ 
turnus on its eastern and southern sides respectively. 
Many other names, deduced from particular places, rivers, 
or mountain storms, are given to the winds. There 
are also the morning breezes, which the sun rising 
from his subterranean regions, and acting violently on 
the humidity of the air collected during the night, ex¬ 
tracts from the morning vapours. These remain after 
sunrise, and are classed among the east winds, and hence 
receive the name of zigog given by the Greeks to that wind. 
so also from the morning breezes they called the morrow 
dogiov. Some deny that Eratosthenes was correct in his 
measure of the earth, whether with propriety or other¬ 
wise, is of no consequence in tracing the regions whence 
the winds blow: for it is clear there is a great difference be¬ 
tween the forces with which the several winds act. Inas¬ 
much as the brevity with which the foregoing rules are laid 
down may prevent their being clearly understood, I have 
thought it right to add for the clearer understanding 
thereof two figures, or as the Greeks call them gra, 
at the end of this book. The first shews the precise re¬ 
gions whence the different winds blow. The second, the 
method of disposing the streets in such a manner as to 
dissipate the violence of the winds and render them in- 
noxious. Let A be the centre of a perfectly level and 
plane tablet whereon a gnomon is erected. The ante- 
meridianal shadow of the gnômon being marked at B. 
from A, as a centre with the distance AB, describe a