328 
STATE AGRICULTUEAL SOCIETY. 
arrangement will be better understood than it could be from de¬ 
scription. The saw which makes the cross-cut will be seen, in 
fact, to be placed like a belt or hoop on the circumference of 
the plane circular saw plate which forms the direct cut, and to 
widen gradually out to the breadth required for the cut. This 
hoop saw is not set at right angles to the plane saw, but at the 
bevel which corresponds to the angle of the joint. The seg¬ 
ments which form the saws are held in their places by means 
of cast-iron cheek-plates held on by set screws with square 
heads, and in about one minute the attendant on the machine 
could change all the segments and replace them by others 
having a finer or coarser pitch of teeth if desired. To prevent 
the saws from splintering the wood on its under side, a longi¬ 
tudinal shallow cut is made by a knife-edge at the bottom of 
the dovetail before the helical saws operate on the wood ; this 
is a most important point, and without it good work cannot be 
produced. The engraving above illustrates only the mode of 
forming one part of the dovetail. At the back of the machine 
provision is made for cutting the other part with equal expe¬ 
dition. An arrangement is also provided for raising the table 
so that the dovetailing can be done on a bevel if desired. The 
attendant was all day long besieged by crowds anxious to see 
this machine at work, and certainly he showed great patience 
in altering his machine to convince the sceptical of its wonder¬ 
ful scope and accuracy. 
PE kin’s band sa-vv. 
The substitution of the circular for the reciprocating saw 
was a very important step of improvement. It introduced a 
considerable economy of the force employed, and a still larger 
economy of time. The reciprocating saw occupies as much 
time in raising as in descending, and is therefore effective only 
during one-half the period of the operation. But the continu¬ 
ous action of the circular saw is attended with the additional 
advantages that it can be run at a higher rate of speed than is 
possible for the older form, and that it admits of a heavier 
feed on account of the steadiness and regularity of the contin¬ 
uous cut. 
