490 I'HILOSOPHICAL TRANSACTIONS. [aNNO I76O. 



The diameters of columns are of less authority than any other horizontal 

 measures; not only on account of the difficulty of measuring them correctly, but 

 because errors of workmanship, to which they are more liable than square mea- 

 sures, more sensibly affect the magnitude of the foot in small measures than in 

 large ones. 



Uprights, of any considerable height, are of less authority than horizontal 

 measures, from the difficulty of taking them correctly ; and being designed by 

 modules, few of them answer well to the foot measure. But here we must ex- 

 cept such shafts of columns as are of one block of marble; which seem to be as 

 good authority as any part of a building: for the necessity of making them all 

 exactly of the same length, must produce accuracy; and the doing this was no 

 difficult piece of workmanship. Being likewise commonly (if not always) wrought 

 at the quarry, to save expence in the carriage, they were probably bespoke to 

 some sijnple measure ; and we shall find all such shafts answer to some number 

 of whole palms. 



In this ingenious way then Mr. R. took the measures of the principal parts of 

 a great number of the ancient Roman buildings, and divided them by the most 

 probable divisors, for the near length of the foot. These quotients fall mostly 

 between the numbers 963 and 972, that is, of such parts as the London foot 

 contains 1000. And at length Mr. R. concludes thus : 



It appears from the measures of these buildings, that the Roman foot before 

 the reign of Titus exceeded 97 parts in 1000 of the London foot, and in the 

 reigns of Severus and Dioclesian fell short of 965. Whether this difference 

 proceeded from any alteration in the standard, or from a false measure of it 

 being got into common use, either before the reign of Titus or after, is uncer- 

 tain. We have no account of any alteration made by law in the Roman stan- 

 dards after the Plebiscitum Silianum, quoted by Festus ; but as great a difference 

 as this might arise from their having been lost or destroyed. 



Thev were kept in the capitol ; and Rigaltius, from a passage in Hyginus, 

 observes that the standard of the foot was deposited in the temple of Juno Mo- 

 neta. Now the capitol was burnt no less than 3 times; first in the civil war of 

 Sylla, then again when Sabinus was besieged in it by the troops ofVitellius; 

 and the 3d time in that dreadful conflagration which happened in the reign of 

 Titus. Whether the standards were destroyed in the first of these fires is uncer- 

 tain ; but they could hardly escape the fury and confusion of the 2d, when, ac- 

 cording to Pliny, the temple of Juno Moneta seems to have been burnt to the 

 ground. And if we may credit Xiphilin (whose account of the 3d is in some 

 measure confirmed by Spartian), not only the temple of Jupiter Capitolinus, but 

 those adjoining to it, were burnt down in the last. 



Vespasian rebuilt the capitol after the 2d conflagration, and restored the 



