METHOD OF SAWIN» CAST IRON. 9,7^ 



pily applied in many arts. I thank you much for having sug- tensive use. 

 gested it to me, for I shall find frequent occasions for it. 



Note by Mr. d' As get. 

 Several years ago Mr. Pictet observed a workman saw a Practised some 

 cast iron pipe in the workshop of Mr. Paul, of Geneva. He years ago at 

 had lately occasion to mention this to Mr. Thenard, who after- 

 ward communicated it to Mr. Mollard. Mr. Mollard, struck 

 with the uses to which it might be applied, tried it at the Con- Experiments 

 servatory of Arts and Trades on pieces of cast iron 7 cent, at Paris. 

 [275 in.] square, and on plates of different thicknesses. 



Mr. Mollard used a common saw, and succeeded perfectly 

 with these various pieces, without injuring its teeth. He ob- 

 served, that the iron should be heated only to a cherry red j and Instructioas. 

 that it should be cut briskly, using the whole length of the 

 saw. Mr. Mollard afterward found, that this process was Known to 

 known to a workman of Mr. Voyenne, who practised it in others, 

 fitting the cast iron plates used for making stoves. It is pro- 

 bable, that this simple operation may be known in other work- 

 shops J but it is lost, as it were, since persons of distinction in 

 the arts are generally ignorant of it. 



We see, that the experiments mentioned in Mr. DufauJ's The practica- 

 letter confirm the account of Mr. Pictet, and the trials of Mr. ^-'''^y demon- 

 Mollard : of course there remains no doubt of the possibility 

 of cutting cast iron when hot, or of the utility of the process. 



We conceive it would be practicable to employ it in the fa- ^^^^ ^^ which 



brication of iron cannons, for cutting off the cap of the piece, it may be ap- 



and even for removing the square piece left at the extremity off " 



the button, which serves for mounting it on the boring machine. ^" ™^ "• *^^°' 



Perhaps advantage might be taken of the red heat, which the 



cannon retains long after it is cast, for sawing off the cap in the 



mould itself, its upper part only being rem.oved. 



The same process would certainly furnish an easy and ready 



^ \ , , , . destroving or 



method of cutting a cannon to pieces, and thus rendermg it remelt'ing 



unserviceable ; or facilitate its melting in the reverberatory them, 



furnace, v/hcn required to be cast afresh. Perhaps it might be 



employed also to ascertain the different ranges of a piece of ^^,^1 ascertaiu- 



cannon, shortened by little and little. It seems to us, the ing their 



knowledge of a practice applicable to so many purposes of the'^"-^'" 



arts cannot be too generally made known. 



Vol. XXXIII> No. 154.— Decfmber, 1812. T VI. 



