572 PHILOSOPHICAL TRANSACTIONS. [anNO 1/95. 



than here; though its timber is less durable, from the numerous pores attending 

 its slow growth. The climate of this country being colder than its native, may 

 in the same way add to the durability of the elm ; which may possibly be further 

 increased by its not producing seeds in this climate, as the life of many annuals 

 may be increased to twice its natural period, if not more, by preventing their 

 seeding. 



XF. On Welding Cast Steel. By Sir Thomas Frankland, Bart., F. R. S. 



p. 296. 



The uniting of steel to iron by welding is a well-known practice; in some 

 cases for the purpose of saving steel, in others to render work less liable to 

 break, by giving the steel a back, or support, of a tougher material. Ever 

 since the invention of cast steel, or bar steel refined by fusion, it has generally 

 been supposed impossible to weld it either to common steel or iron ; and natu- 

 rally, for the description in Watson's Chemical Essays, (vol. 4, p. 148) is just, 

 that in a welding heat it, " runs away under the hammer like sand." How far 

 the Sheffield artists, who stamp much low-priced work with the title of cast 

 steel, practise the welding it, I am ignorant; but though I have inquired of 

 many smiths and cutlers in different parts of the kingdom, I have not yet found 

 the workman who professed himself able to accomplish it. If therefore I should 

 describe a simple process for the purpose, I may be of use to the very many who 

 are incredulous on the subject. 



If any one has made the discovery on principle, he has reasoned thus: cast 

 steel in a welding heat is too soft to bear being hammered; but is there no lower 

 degree of heat in which it may be soft enough to unite with iron, yet without 

 hazard of running under the hammer ? A few experiments decided the ques- 

 tion; for the fact is, that cast steel in a white heat, and iron in a welding heat, 

 unite completely. It must not be denied that considerable nicety is required in 

 giving a proper heat to the steel ; for on applying it to the iron it receives an 

 increase of heat, and will sometimes run on that increase, though it would have 

 borne the hammer in that state in which it was taken from the fire. I need 

 scarcely observe, that when this process is intended, the steel and iron must be 

 heated separately, and the union of the parts proposed to be joined effected at a 

 single heat. In case of a considerable length of work being required, a suitable 

 thickness must be united, and afterwards drawn out, as is practised in forging 

 reap-hooks, &c. The steel on which my experiments have been made, are 

 Walker's of Rotherham, and Huntsman's, between which I discover no dif- 

 ference; and though there may be some trifling variation in the flux used for 

 melting, they are probably the same in essentials. 



