[ 4^7 ] 
on a coin, I fee no reafon to fuppofe it hath lofl any 
fenfible part of its original weight. 
In the following dilcoufe, I have colledled the 
moll authentic evidence I could find, 'of the weights 
of the Attic Drachm and the Roman Denarius > part 
of which I have taken from that very valuable pub- 
lication of the Pembroke collection of coins. But, 
valuable as it is, it would have been more fatif- 
faCtory to the accurate perufer, if the Noble Editor 
had diftinguiflied the degree of prefervation the fe- 
veral coins were in, and given the weights of the 
molt perfect, nearer than to half a grain. 
In the year 1759, by the favour of the learned 
and ingenious Dr. Gowin Knight, Principal Libra- 
rian of the Britifh Mufeum, I weighed a confidera- 
ble number of the moft perfeCt Greek and Roman 
coins in that noble Repofitory. 
The fcales I ufed were good workmanfhip, of the 
' common conftruCtion, made by Read j the beam 8 
inches, and they turned freely with lefs than the 
20th part of a grain. To avoid any error, I weighed 
each piece in both pans. My weights were moft 
accurately fized; and, upon comparing the Troy 
ounce I ufed, with that in the archives of the Royal 
Society, in an exquifite balance of my late much 
efleemed friend. Dr. Henry Pemberton, it was 
found to be ^ of a grain heavier, which I have al- 
lowed for in the following difcourfe. 
This effay hath received very confiderable ad- 
ditions from the ineftimable treafury of ancient coins, 
in the pofiTeflion of the learned Matthew Duane 
Efq; who moft obligingly afiiftcd me in taking the 
weights of fuch as were for my purpofe. And it 
O 0 o 2 was 
