[ 4x8 ] 
A fhort account of the Authors , from whofe 
writings and experiments , the following Tables 
have been collected, with fome remarks upon 
the experiments t hemj elves, and the manner in 
which they appear to have been made . 
T HE antients have left but few particulars con- 
cerning the different fpecific gravities of bodies, 
tho’ it is plain they were in the general fufficiently 
acquainted with them. It was by the knowledge 
of the various weights of gold and filvcr, that Ar- 
chimedes is recorded to have detected the famous 
fraud committed in Hieros crown, as Vitruvius has 
at large related in his Architecture, 1 . ix. c. 13. 
and it is from the fame great philofopher, that we have 
derived the demonftration of thofe hydroftatical 
Tules, by which the proportions are beft to be 
known, of the feveral weights or denftties of dif- 
ferent bodies, having the fame bulk or magnitude : 
as may be feen in his tract De infdentibus humido , 
loft in the Greek original, but retrieved in great mea- 
fure, as it is faid, from an Arabic tranflation. It 
was publifhed in Latin , with a commentary by 
Federicus Commandinus at Bononia if 6 f, 4 0 , and 
the fubftance of it by Dr. Barrow in his Archimedes, 
printed likewife in 4 0 at London 1675. 
Bliny , in the xviii. book of his Natural Hijtory, 
has fet down the proportional weights of fome forts 
of grain, among which he fays that barley is the 
lighted. Levijfimum ex his hordeum , raro excedit , 
[in fingulos nimirum modios] xv libras, et faba xxii. 
Tonderojius 
