C 354 ] 
of burning Mountains, in this Solar Fire, melts into a 
white cranfparent Glafs. ( 1 1 ) A piece of a very ftrong 
Crucible put in the Focus j in 8 Minutes was melted into a 
Glafs. (^12)1 have likewife feen Bones turned into a 
kind of Opake Glafs, and a clod of Earth into a yellow or 
greenifli Glafs. 
It is to be noted that I made thefe Experiments in the 
htttvQnd oi Augufi 2i\\A September^ when the Sun has not 
the fame Force as when he is about the Summer So'ftice ; 
at which time I promife my felf yet more wonderful ef- 
fefts ; tho from hence it is evident, that there is no other 
Fire in Nature of the like Force and Efficacy. 
I might add feveral other things well worth Notice, but 
fiiall only give you this one. I tryed what effed the 
Beams of the full Moon, concentred with this Spemlumy 
would have, at the time when ihe was at hergreateft 
Altitude ; but there was not found any degree of Heat, 
tho' the Light was not a little encreafed. 
This paflage of thQ Lipfick Journall was produced at 
one of the meetings of the Royal Society by Mr. Ho k^ as 
feconding a propofal he had fbme Years fince made to 
them concerning the fame thing. He fuppofed that if 
fuch 2i Speculum were made of many Foot diameter, its eft 
fefts muft needs be prodigious ; and might be of great ufe 
in perfeSling the Art of Pafts or Faftitious Jewells, which 
require the moft intenfe degree of Heat, to bring them to 
an exaO: mixture. He conceives fuch an one might be 
made very large for a fmall Price, being hammered out of 
^ Copperplate, and tinned over with a mixture of Tin, ■ 
Lead and Tin-glafs, which is found to bear a very good j 
Polifh. I 
LONDON i 
; 
Printed by J. Str eater, and are to be Sold by Sm^ ^Mfk ' 
at the Prmces Ames in St. PauUs QhmhjArd. " * ^ ] 
