86 
THE YOUNG SCIENTIST. 
into the line, but rather to cut it from the 
sides in order that each line may be 
thoroughly clean. 
The graver is used to increase the dark- 
ness of small portions, and is used in the 
hand as follows : 
Fig. 13. 
How to Make Emery Wheels. 
BY W. B. HARRISON. 
"Xj^MEEY wheels should be made from 
J-^ clear, soft pine stuff that is well sea- 
soned. By clear stuff is meant boards 
that are free from knots, cracks, or cross 
grain. These boards should be planed 
smooth on both sides, and then sawed 
into circular pieces a little larger than 
the finished wheel is to be. It is best to 
glue two or more of these circular pieces 
together, and glue them so that the grain 
of each piece will be at right angles to the 
one to which it is attached. If the stuff 
be inch thick when unplaned, it will be 
about seven-eighths of an inch thick 
when planed, and two of these pieces 
:glued together will make a wheel of 
ample thickness for the use of the ama- 
teur mechanic. 
If it be desired to make the wheel very 
strong, bore six or eight half-inch holes 
through the wheel, equi-distant from each 
other, within an inch or so of the peri- 
phery. Make pins of soft pine to fit these 
holes, coat them with glue, and drive 
them in snug, sawing off the projecting 
ends. The glued work must be thoroughly'' 
dry before advancing further. The next 
step is to form the discs into wheels, and 
the first proceeding is to make the hole 
to fit the spindle on which it is to revolve. 
To bore these holes with a bit or auger 
would, in all probability, result in a hole 
that would not be at a right angle with the 
side of the wheel. The proper way is to 
fasten the discs to the face-plate of a 
lathe, with screws inserted in holes from 
the back side the plate. "When so fastened 
that it will revolve true, a gouge or nar- 
row chisel can be used to cut the hole, 
and it can be made very nice and true. 
Take care to make it to fit the spindle on 
which it is to run. If an iron or metal 
bushing is to be inserted in the hole, turn 
out enough so that it will fit nicely in 
place before the wheel is removed from 
the face-plate. 
The next step is to put it on the spindle 
on which it is to run, using a gouge to 
rough it into a circular form, and a chisel 
to make the surface smooth. The sides 
can now be turned up true. The periphery 
of the wheel must be covered with thick 
leather, and for this purpose the same 
kind of leather that belting is made of is 
generally used. Many mechanics get 
leather belting for this purpose. When 
all is ready, and a kettle of good glue 
prepared, lay one end of the leather on 
the circumference of the wheel and fasten 
it there with two or three shoe pegs. 
Insert the pegs in both leather and wheel 
by driving them into holes made for the 
purpose with a bradawl. Remove the 
leather with the pegs in it, spread the 
glue from the holes made for the pegs for 
a little distance in the direction in which 
the leather is to be put on, put the leather 
in place, inserting the pegs in the holes, 
and drive them home wath a hammer. 
When glueing the leather, it is best to 
hold the wheel firmly in a vice, or stand, 
in such a manner that the leather can be 
pulled tight on the wheel as it is being 
glued. After pegging the edges of the 
leather as far as glued, at intervals of an 
inch or so, put on more glue, and so pro- 
ceed until the end is reached, where it was 
first fastened ; cut off the leather so that 
it w^ill just meet this end; form a close 
joint ; glue it well and securely peg it in 
place. Lay the wheel aside until the glue 
is thoroughly dry. The wheel may then 
be put on the spindle in the same way it 
was when turned, and the leather turned 
off true and smooth with a sharp gouge, j 
finishing it with a sharp chisel. I 
Glue of only the best quality ought to 
be used in making emery wheels, and 
especially to fasten the emery to the 
leather surface. Prepare the glue as for 
glueing wood, and use it pretty hot, taking 
care that it is not too thick. The emery 
