THE

THIRTEENTH B 0/0 K

OF

Natural Mamck

Os tempering Steel.

The Proem e.

I Have taught you cowering monstresu Fires ; aud, before I part from them , Ist HI treatof Iron Mmes ; for Iron u wrought by Fire : not that / intend to handle the Art

J. of Iron Mmes ; for Iron u wrought by Fire i not that I intend to handle the Artof it ; but onely to Jet down some of the choicest Secrets that are no less necessary for theuse of men, in thoje things I have jpokenef already , besties the things IJ pake of in my Chy-

mtcal works. Of Iron there are made the best ana the worst Instruments scr the life ofptan, faith Pliny. Fer we use it for works of Hub an dry end building of Houses • andwe u(e it for Wars and Slaughters : not onely hard by ; hut to shoot with Arrows , andHarts, and I uUtts,far off. For , that man might die the sooner , he hath made it swift , andhath j ut wings to Iron. / fhaUteachyou the divert tempers of Iron , and how to make itsoft and hard that it stall not onely cut Iron and other the hardest substances , but fhaUengrave the hardest Torphyr and Marble Stones, In brief the force of Iron conquers aHthings i

Cha*. I.

That Iron by mixture may be made harder.

T is apparent by most fsmeus and well-known Experience,!that Iron will gitw mere hare b) being wrryered, and bewade iofe also. Aid when I l ad serght a long t'me whe-ther it would grrw left rr hare I y hr t, cold, moist or drythings; I found that hot thing? wr uld make it hard and soft,and so would cold and all the other qualities; wherefore lem-thing else must be thought en to hum cur (because?. Isound that it will grow hard by its contraries, antsfofr bythings that are friendly to ir; and so I came to S\ mpathy and

Antipathy. The Ancients thought it was dene by feme Supeiltiticu Wufhip, andthat there was a C hain of Iron by the River Euphrates, that was called Zeugma,wherewith Alexander the Great bad there bound the Bridge ; and . thatjhe links ofit that were new made, were grown rusty, the other links nbt being so. Tliny and.others think, That this proceeded from some different qualiiies ; it may be femejuices or Minerals might run underneath,that left feme qualities, when by Iron mightbe made hard or soft. He faith. But the chief difference i? in the water that it isoft plunged into when it is ted hot. The pre-eminence of Iron that is so profit-able, hath made some places famous here and there; as Bilbili? and Turaflio in Spain,Ccmumin Italy: yet are there no IroD My nes there. But ok all the kindes, theSeric hen bears the Garland ; in the next place , the Parthian : dor are there anyother kindes of Iron tempered of pure Steel : for the rest are mingled. Jultmethe Historian reports, That in Gallicia of Spain, the chitft st matter for 1 ron st found;but the water there is more forcible then the Iron : for the tempering with that,makes the Iron more ftiarp. End there is no weapon approved amongst them, that

Tt