FRANCIS WILLUGHBY. 
67 
to Cirencester, but hearing by the way of a great 
deal of treasure that was found in a field, I 
presently conjectured that it might be a Roman 
coin, and directed my course thither. The field 
was near Dursly, a town we left about a mile of 
the left hand as we rode from Glocester, where I 
found above forty people digging and scraping, 
and bought a great many silver medals of them, 
and one incomparable fair one of gold that had 
been found a little before. The whole history 
how these came to be discovered 1 shall Reserve 
till I see you. I thought to have made strict 
inquiry after the snap-apple bird, but falling very 
sick at Malverne, I was forced to give all over.” 
There is also proof that Mr Willughby had, by 
this time, made high attainments in mathematical 
learning. In the Philosophical Letters there are 
two addressed to him by Dr Barrow; the One 
dated Trin. Coll. March 26, 1662, and the other, 
October 5, 1665. 
In the first of these, Dr Barrow speaks of Mr 
Willughby’s observations concerning “ the spiral 
line, as having sufficiently evinced the invalidity 
of a supposed demonstration concerning its 
equality with the semi-periphery.” In the 
second letter, he says, — “ Your -discourse infer- 
ring the solidity of the sphere from the surface, 
by comparing the concentrical surfaces of the 
sphere with the parallel circles of the cone, is very 
ingenious and solid,” &c. “ Your observation 
about the equality of the annuli, with spherical 
portions, is also true and ingeniously proved.” 
