244 farmers' and mechanics' journal. 



he thought there would be httle difticulty in, applying his improve- 

 ment to the teeth of all saws, which were not exceedingly small, 

 lie would screw the saw fast in a vice, (the teeth in the chaps of 

 which were guarded fronn indenting the saw, by plates of copper 

 lining the chaps on each side,) and, with the flat cross-pane of a 

 hammer, the handle of which was held towards the fore part of the 

 saw, and the hammer itself at a proper angle, to suit the form of 

 the teeth, he would then hammer-harden every individual tooth. 



The best saws are those which have been considerably condens- 

 ed by hammer-hardening them on their sides, in making them ; but 

 this additional process, of hammering the tops of their teeth, can- 

 not but prove a considerable improvement upon them. 



[Technical Repositoi-y. 



On the great improvement made in Brick-layers'' Trowels, hy Ham' 

 mer -hardening them. By Mr. George Walby. 



There is, perhaps, no implement which undergoes more severe 

 treatment than the brick-layer's trowel does, in its constant em- 

 ployment of hacking bricks into shape, and thus encountering the 

 pieces of flint, pebbles, &c., ordinarily mixed with the clay ; and 

 which, besides having a tendency to injure its edges, also render it 

 liable to break continually. Mr. Walby, therefore, by his excel- 

 lent processes, accomplished a most dilllcult task, and rendered his 

 superior trowels highly prized, by those persons who were the 

 most competent judges of their merit, from their constant expe- 

 rience in their use ; and, indeed, his brick-trowels, like the hand- 

 saws made by the Editor's late father, were continually changed, 

 by grinding, into other and smaller kinds, until they became too 

 diminutive for any useful purpose ; their originally excellent quali- 

 ty remaining perfect to the last. 



They were made of the best shear-steel, carefully worked 

 throughout, and especially to avoid over-heating the steel ; and 

 towards their finishing in the plating or forging, and when nearly 

 reduced to their proper thickness, besides beating them in a clean 

 hollow-fire, to avoid contact with cinders, &c., he also removed all 

 scales upon their surface, previous to giving them their last planish- 

 ing, under the rapid blows of a hammer driven by a steam-engine, 

 by means of a very ingenious revolving elastic steel brush of his 

 invention. He carefully attended to the proper hardening heat, 

 and quenched them in a composition or hardening liquor, similar 

 to those used by saw-njakers : he next blazed them off to the spring 

 temper ; and, lastly, hammer-hardened them as much as possible. 

 They were then ready for grinding, after which operation, their 

 elasticity being again restored by blueing them, they were glazed 

 or brightened, ready to be mounted into their handles. 



We have many particulars of the various tools, used by Mr. 

 Walby in his practice of trowel-making, and which are well de- 

 serving of being published. 



