On Heat.— Method of welding Cajl-Steel. 575 



remain very cold during the fpring, and probably during the greateft part of thefummerj 

 and tliis could not fail to chill the atmofphcre, and check vegetation in the furrounding 

 country to a very confiderable diftance. And though a large lake of fait water in a cold 

 country would tend to render the winter fomewhat milder on one fide of it, namely on the 

 Ijde oppofite to the quarter from whence the cold winds came ; yet tixis advantage would 

 rot only be confined to a fmall traft of country, but would not any where be very import- 

 ant, and would by no means counterbalance the extenfive and fatal confequences which 

 would be produced in fummer by fo large a colleftion of very cold water. 



When the winter is once fairly fet in— when the earth is well covered with fnow, and 

 the rivers and lakes with ice, and more efpecially when the ice as well as the land is covered 

 ■ with that warm winter garment, a few degrees more of cold in the air cannot produce any 

 lading bad confequences. It may oblige the inhabitants to ufe additional precautions to 

 guard themf-lves, their domeftic animals, and their provifions, from the uncommon fcverity 

 of the weather; but it can have very little influence in the temperature of the enfuing 

 fummer; and it is even probable, if it influences it at all, that it tends rather to make it 

 warmer than colder. Lakes of fait water could therefore be of no real ufe in winter in 

 cold countries, and in fummer they could not fail to be very hurtful ; while frefh lakes, as 

 tliey are frozen over almofl as foon as the winter fets in, and long before the whole mafs 

 of their water is cooled down to the temperature of freezing, muft preferve the greater 

 part of their heat through the winter ; and if they are of no ufe during the cold ieafon, 

 thcv probably do little or no harm in fummer*. 



X. 



Ujeful Notices refpe^ing various OhjeBs. — JVe/ding ofCaft-^teel — Flexure of Compound Metallic 

 Bars by Change of Temperature. 



I. Welding of Cafl-Steel. BySirTHOMdS FraNKLAND, Bart.f 



J. H E uniting of fteel to iron by welding is a weH-known praftice ; in fome cafes for 

 the purpofe of faviag (leel ; in others, to render work lefs liable to break, by giving the fteel 

 a back or fupport of a tougher material. 



Ever fince the invention of caft-fteel (or bar-fteel refined by fufion) it has generally been 

 fuppofed impofiible to weld it either to common (leel or iron ; and naturally — for the dc- 

 fcripiion in VVatfon's Chemical llflays (vol. iv. p. 148) is juft, that in a welding heat it " runs 

 away under the hammer like fand.'' How far the Sheffield artifls, who ftamp much low- 

 priced. work with the title of cail-fleel, pra£life the welding it, I am ignorant ; but though 

 I have enquired of many fmiths and cutlers in different parts of the kingdom, I have not 

 yet found the workman who profcfled himfelf able to accomplilh it. If therefore I fliould 

 defcribe a fimple procefs for the purpofe, I may be of ufe to the very many who are incre- 

 dulous on the fubje£l. If any one has made the difcovery on principle, he has reafoned 

 thus : Caft-fteel in a welding heat is too foft to bear being hammered ; but is there no 



'* Throughout this ElTay, but more particularly in the lad chapter, the author has very (Ironjjly infiftcil oa 

 the final caufct of the laws he has endeavoured to dcvilope. I have no wilh at prcfcnt todifcufs tlic qucllion, 

 how far the propagation of truth may be advanced by fpcculations on chofc caufes ; but have added this note, 

 left I fliould be thought to have mutilated his ElTay by leaving out fo fliiking a part. My aim has been ta^ 

 communicate his phyfical diftoveries only. N. 



t Phil. Tnior. M.DCC.xcv. »9'- 



lowCE 



