036 PHILOSOPHICAL TRANSACTIONS. [aNNO 1683. 



brick buildings to be made within the city of Rome, as a thing not of choice, 

 but necessity, these brick buildings being certainly, in that great architect's opi- 

 nion, to be preferred : the law, says he, suffers not a wall to be made to the 

 street-ward above a foot and a half thick, and partition walls th'e same, lest 

 they should take up too much room. Now brick walls of a foot and a half 

 thick, unless they were diplinthii or triplinthii, cannot bear up above one story; 

 but in so vast and majestic a city as old Rome, there ought to be innumerable 

 habitations ; therefore when a plain area or building of one story could not re- 

 ceive such a multitude to dwell in the city, the thing itself compelled them to 

 raise the houses higher, and therefore they had strange contrivances of out- 

 jetting, and over-hanging stories and balconies, &c. ; which reasons if rightly 

 considered are great mistakes ; for at this day it is demonstrated that a firm 

 building may be raised to many stories height upon a foot and a half thick wall. 

 The oversight of the Romans was the vast size of their brick ; for the smaller 

 the brick the firmer the work, there being much greater firmness in a multitude 

 of angles, as must be produced by a small brick, than in a right line; and this is 

 the reason of the strength of buttresses and multangular towers, &c. 



Those bricks are about 17 inches of our measure in length, and about 11 

 inches broad, and 2 inches and a half thick ; agreeing very well with the notion 

 of the Roman foot, which the learned antiquary Greaves has left us; viz. of its 

 being about half an inch less than ours; they seem to have shrunk in the baking 

 more in the breadth than in the length; which is but reasonable, because of their 

 easier yielding that way ; and so for the same reason, more in thickness, if we 

 suppose them to have been designed in the mould for 3 Roman inches. 



This demonstrates Pliny's measures to be right, and not those of Vitruvius, 

 as they are extant; which makes me much wonder at the confidence of Daniel 

 Barbarvis affirming the bricks now to be found, are all according to Vitruvius 

 and not Pliny's measures; for all that I have yet seen in England are of Pliny's 

 measures; as at Leister in the Roman ruin there, called the Jews Wall; at St. 

 Albans, as I remember, and here with us at York. And to go no farther for 

 arguments than this very chapter of Vitruvius, the diplinthii parietes in Rome 

 were against law, and the single brick wall was only allowed as standard, viz. 

 a foot and a half thick wall, or one Roman brick a length, as was above 

 noted. 



Pliny lived sometime after Vitruvius, and being a professed transcriber, and 

 as it appears from this very place, having taken the whole business of brick 

 almost verbatim out of him, and not differing in any one thing in the whole 

 chapter, but in this, or the measure of the didoron ; and the bricks demon- 

 strating the truth of that difference, it is but reasonable we should make Vitru- 



