THE YOUNG 
Jiave about three teeth to the inch. There 
should not be more than this number, 
but there may be less, as two and a 
half teeth to the inch will give very fair 
satisfaction, but it requires more force to 
drive a saw this coarse tnrough the wood 
than if the teeth were liner. 
The blade of a rip-saw should be a little 
stiffer than that of a crosscut, and should 
be perfectly straight, and ground thinner 
on the back than on the cutting edge ; 
this will admit of the saw having less set 
than would otherwise be required. The 
shape of the teeth should be about as 
shown at Fig. 2. It will be noticed that 
the teeth are underfiled, or that the cut- 
ting face forms an acute angle with the 
line of teeth. If the cutting face of the 
teeth form right angles with the cutting 
edge the saw will not work free and with 
ease, as the teeth will not cut the wood, 
but rather pound out the sawdust. Each 
tooth should act on the end grain of the 
Fig. 2. 
wood, as a narrow chisel would ; and to 
do this it is quite necessary that the teeth i 
should be underfiled, or made hooked, as 
shown in the flgtu^e, but care must be 
taken not to give too much hook, for in 
that case the teeth would be made weaker 
at the base, and would be apt to break off 
under the operation of setting, or if the 
saw should run foul of a hard knot while 
in use, the same result might follow. 
While it is necessary to warn the filer 
against making the teeth too much 
hooked, it is just as necessary to inform 
him that a limited amount of hook is re- i 
quired to give clearance to the sawdust. 
If the throats or gullets of the teeth are 
too small— which would be the case if the 
teeth were not filed under a little— the 
sawdust would fill up the spaces between 
the teeth, if the stuff being cut was more 
than a couple of inches thick, and there- 
in SCIENTIST. 77 
fore impede the progress of the saw, caus- 
ing a loss of time and labor. 
For amateur use the teeth shown at 
Fig. 2 are probably the best in shape, if 
for soft wood only. If, however, the saw 
is intended to cut hard wood, the teeth 
might have a tritie less hook and be tiled 
a little beveling on the face, being careful 
not to file the back of the teeth beveling. 
Saws intended for ripping hard wood 
only may have more teeth to the inch 
than those intended for cutting soft wood. 
From four to five teeth to the inch will 
answer very well for amateur use on hard 
wood, though this is somewhat finer than 
the expert workman uses for the same 
purpose. The fewer the teeth in a saw 
within certain limits the faster it will cut, 
but as a matter of course will require 
more force to drive it through the ma- 
terial, and the work will not be so 
smoothly done as if performed with a saw 
having more teeth. 
In using a rip-saw, the amount of work 
done in a given time depends somewhat 
on the angle at which the saw is held 
while in use. The position and inclina- 
tion of the tool, as shown at Fig. 3, is the 
most convenient and at the same time the 
most efficient inclination for the saw to 
Fig. 3. 
be held. If tipped over until the line of 
teeth is parallel with the dotted lines, it 
will scarcely cut at all, owing to the fact 
that the tliroats would be choked with tlie 
shavings scraped off the wood by the 
points of the teeth. If held perpendic- 
ular, the points of the teeth will strike 
the fibres square across their ends, which 
will make it severe on both saw and saw- 
yer. 
The clamps used for liolding a crosscut 
saw while being filed will answer for the 
