Fate and CbaraBer of the Monk Roger Bacon. 327 



refult ; fo that it feemed deducible from it, that y th part of 

 carbon in addition to any quantity of iron was infiifficient to 

 form fteel ; and, referring to the refult of No. VI., it appeared 

 that even ~th part formed a fteel much too foft for the ge- 

 neral pnrpofcs of manufatture. This conclufion, however, 

 being at variance with fails I had already cftablifhed upon 

 the formation of caft fteel in common crucibles, was here 

 inadmirtible. It was therefore ncceffary to fcek for an ex- 

 planation of the phsenomenon of the charcoal difappcaring 

 in clofe veffels, formerly alluded to, before any certain know- 

 ledge of the e.xaft quantities of charcoal could be afcertained, 

 which were necefTary to form either caft iron or fteel in vef- 

 fels made impervious to the air *. I uniformly remarked in 

 the prefent experiments, that when the quantity of charcoal 

 introduced was from ^'^th to ^^|,-^th the weight of the iron, 

 a portion of glafs was conftantly formed upon the furface 

 of the metallic button. The quantity generally increafed as 

 the proportion of charcoal decreafed; fo that, in fome experi- 

 ments, 300, 350, and 400 grains of amber-colour glafs was 

 obtained. The upper furiace of this glafs was frequently of 

 a pure pearly white colour. In one experiment, where y'oth 

 of charcoal was ufed, I obtained a large quantity of glafs cel- 

 lular throughout. Each cell was furmounted upon the top 

 with concentric circles of pearly lines, forming a curious and 

 pleafing eflTeft. 



Having fully fatisfled myfelf that operations performed in 

 clofe veflels thus prepared were fubie(51 to uncertainty, arifing 

 as well from the formation of glafs as from fome unknown 

 affinity exerted upon the charcoal; and having performed fe- 

 veral experiments with well filled open crucibles, with char- 

 coal alone, wherein I found little comparative lofs, I per- 

 formed a very accurate feries of experiments, which (liall be 

 forwarded for the next number of the Magazine. 



l^Vr. On the Tale and CharaHer of the Monh RoGP-B 

 Bacon. By Governor Pownall. Read before the 

 Literary and Phltofophtcal Society ^ Bath f. 



X HERE has been much bufilc about learning in the 

 i\T)rld : every age has had its learning; the produce and 

 growth of a defultory ac^tivily of the imagination, according 

 to the faniion of thinking prevalent at the time: whilft the 



* This invefligation will form a fcjiarait pap r for July, 

 t C'oininuiiiciicil by tlic Author. 



X 4 flow 



