[ 792 ] 
afterwards reduced to Paris toifes ; or by a wheel, 
which is liable to great errors : therefore we cannot 
allow much authority to it, unlefs we were better 
allured of its accuracy. He quotes the Marquis Maf- 
fei for a meafure of 756 toifes between two other 
mile-ftones on the fame road ; but obferves, that they 
were fet up by different emperors, Auguftus and Ti- 
berius, and that the road formerly made an elbow 
between them, whole pofition is now not certainly 
known. Therefore this meafure, which gives a 
foot of y 66 i London parts, is likevvife of fmall au- 
thority. 
All that can be determined from fuch uncertain 
and difcordant data, as I have here collected, is a 
meafure that fliall probably be neither the greatell 
nor the leaft magnitude of the Roman foot. And 
for this, 1 fliall take a mean from all the meafures 
above recited, which is nearly p68 thoufandth parts 
of the London foot. 
Before I enter upon the examination of the antient 
buildings, it may be proper to fay fomething con- 
cerning the nature of the evidence to be expected from 
them. 
All buildings are planned and executed by fome 
meafure of the country where they are built. At 
Rome this meafure was the foot, which was divided 
by the workmen into 4 palms, and each palm into 
4 digits (8). 
(8) Vitruvius, lib. iii. c. 1 . Frontinus de Agrorum Qualit. 
Both thefe authors are technical writers, and give this as the di- 
vilion ufed by workmen; and the antient foot-rules are fo divided. 
They 
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