Of tempering Steel . 307

The temper of a Knife to cut Bread.

I have seen many ingenious men thai laboured for this temper, who, having Knivesfit to cut aii hard substances, yet they could scarce fall upon a temper to cut Breadfor the TabiC. I tuihiled their dtlire witn such a temper. Wncrefore to cut Bread,let the Steel be loftly tempered thus: Heat gently Steel, that when its broken leemsto be made of very small grstns; and let it be excellent well purge d from Iron: thenstrike it with a Hammer to make a Knife of it: then work it with the File, and frameit like a Knife, and polish it with the Wheel: then put it m.o the Fire, uU it appearViolet-coiOUf. Rub it over with Sope, that it may have a better colour trom the Fire:theD take it from the Fire, and anoynt the edge of it with a Linen-cloth dipt in Oyiof 0‘ives, until it grow co,d ; so you (hall loften the hardness of the Steel by thegentleness of the Oyl,*nda moderate heat. Not much differs from this,

Tie temper of Iron for Wood. t <

Something harder temper is fit to cut wood ; but it mt, 1 be gentle also : thereforelet your Iron ccmeto the lame Violet-colour, and then plunge it into waters: rakeit out; and when it appears Afh-colour, call it in.,6 cold water. Nor is there muchd.fference in

The temp r for Instruments to let blood.

It i-quenched in Oyl, and grows bard ; because it is tender and subtile: for should!t be quenched in water, it would be wrested and broken.

The temper of Iron for a Sythe.

Aster that the Iron is made into a Sythe let it grow hot to the colour of Gold,andthen quench it in Oyl , orsm:er it with Tallow, because it is subtile Iron j andshould it be quenched in waters, it would either crumble or be wrested.

Chap. IV

How for all mixt sites, i ron may be tempered mefi hard.

N Ow I will shew some ways whereby Iron mty be made extream hard : for thatIron that must be used for an ln' ; rutnent to hammer, and polish, and fit otherIron, must be much harder then that.

The temper of Iron for F ties.

It must be made of the best Steel, and excellently tempered, that it rmy polish, andfit o:her Iron as it should bv: Take Ox hoofs,and put them into an Oven to dry,thatthey may be powdered fine: mingle well one part of this with as much commonSalt, beaten Glass, and Chimney-loor, and beat them together, and lay them up foryour use in a wooden Vessel hanging in the 1‘moak ; for the Salt will melt with anymoisture of the place or Air. The powder being prepared, make your Iron like to afile : then cut it chequerwise, and crofswayes, with a sturp edged tool having madethe Iron tender ana toft, as 1 said, then make an Iron chest fit to lay up your files in,and put them into it,strewing on the powders by course,that they may be covered allover : then put on the cover, and lute well the chirks with clay and raw, that the|pioak of the powder may not breath out ; and then lay a heap of burning coals allover it,that it. may be red-hot about an hour: when you think the powder robe burntand consumed, take the chest out from the coals with Iron pinchers, and plunge thefiles into very cold water, and lo they will become extream bard. This is the usualrernper for files ; for we fear not if the files should be wrested by cold waters. But Ishall teach you to temper them excellently

ylnothtr way.

Take the pith out of Goatshorns, anddrv it, and powder it : then lay your filesin a little Chest strewed over with this Powder , and do as you did before. Yetobserve this, That two files supernumerary must be laid in, so that you may takethem forth at pleasure: and when you think the Chest, covered with burning coalsj

It 2 hath;