r ) 
Now vvc are upon this head, I can't help giving you 
nn Account of fcmething i have obferved relating there- 
to." 
About 5 years ago I was in another Town, where they 
fi'ew'd me a Magnifying Glafs, whofe chiefeft Excellency 
was, that one could fee an object a grc'at diftance from 
the faid Glafs. As fccn as ever 1 iiad put the Glafs to 
my eye, I concladed ihat there was a hole or cavity in ir, 
by which the remote obj-ft came to be feen ^ for when I 
v&me CO \iew the Glafs by one of my own v/hich I had 
:.bout me; I did not only difcover one deep Pit or Caviry 
in it, but fevcral other leficr, which had not been gro jnJ 
out ^ fo that upon the whole it fcenfd a very incoafiJc- 
rable Glafs. 
Laft Winter camie to me a Feliow, whofe bunnefs it is 
to grind Clafics, and bragged mightily of a Magnifying 
Glafs that he had, whereby he couid fee into Metals and 
Miners 1?. 
1 laught at w^hat he faid, and made anfwerj that the 
Pores oi Metals w^ere fo clofe and impervious, that it was 
impofiible ever to fee through ihem^ and that Leal-Gold, 
the never fo thin beat, uculd teach us that. 
Keintrcaied me but to give him a minutes time, and 
he did not dcubt but to miike good his Aflerrion 5 here- 
upon he put his Glais into my hands, adding, that I 
(hould fee ^he light of the Candle through a Copper Cir- 
cle wiiich (locd before the Magnitying-Glafs, and accord- 
ingly I faw a very imperfeft light through, the Copper 
Circle. . ' ' - ' 
Hereupon I tbld him that this was ro:hfng 5 that he 
might cheat the Ignorant, but muft not think to impofe 
upon me 5 and that this Phenomenon was only occL^fion'd 
by a fmall part of the Glafs that was not ground ^ and 
then I rook an extraordinary Glafs, which immediately 
difcove^ed thofe parts that were not groamd, and fnewing 
my Gentleman the fame, he was quite amazed, and fo I 
diOiiifl: him. h 
