76 
THE YOUNG SCIENTIST. 
Three Amateur Workers— and 
They Did-lX. 
What 
BY FRED. T. HODGSON. 
NOW," said Mr. Carpenter, on the fol- 
lowing evening, " I will show you how 
to make the furniture for Jessie's play- 
house ; but before we proceed to business 
It will be necessary that you be informed 
on a few matters touching the use of some 
other tools I have procured for you, and a 
style of work you have not yet performed ; 
namely, mortising and tenoning. A mor- 
tise is a hole of some eiven dimensions 
Fig. 31. 
cut into a piece of wood or other material. 
Its object is to receive a tenon which is 
fitted tightly into it, and the two pieces 
th«s framed together generally form a 
right angle. The mortise is made by first 
Fig. 32. 
boring a hole at one end of it with a bit 
not larger than the width of the mortise. 
A chisel is used to remove the other por- 
tions of wood. The chisel is driven into 
the wood with a wooden mallet until 
it is more than half way through the stuff 
being mortised ; the "core," or wood that 
Fig, 33. 
has been moved by the chisel, is then 
pried out of the mortise, and another cut 
is taken, and so on until the mortise is all 
cut on the one side. The piece is then 
turned over, and the same operations are 
gone through. You will notice that the 
mortise is " laid out " or marked on both 
sides of the stuff. On small stuff this is 
accomplished by using a mortise gauge, 
which you see is something like the single 
gauge you have been using, only it has a 
screwed spur, which can be adjusted to 
any width of mortise within the capacity 
of the tool, by a slide that is movable in a 
slot. Sometimes this slide is controlled 
by a thumb-screw, which is attached to 
the end of the stem. 
When the "core" or chips are all 
cleaned out of the mortise with a firmer 
chisel, and the ends properly squared 
down, it is then ready to receive the 
tenon. 
A tenon is formed with a saw, or rather 
with two saws— a rip saw being used to 
cut down the tenon lengthwise of the 
grain, and a back saw for cutting the 
shoulders. The gauge used for mark- 
in the mortises must be used for laying 
out the tenons without being changed." 
Mr. Carpenter then explained how the 
lines were carried over the stuff to show 
the shoulders on the tenons and the ends 
of the mortises, with the try-square. It 
is often a puzzle to young ])eople to dis- 
cover how a line can be carried round the 
four sides of a piece of stuff and join with- 
out any divergence. If a piece of stuff is 
straight and parallel on every side, and a 
true try- square be applied with its stock 
against one edge, and the blade lapping- 
over a side at right angles with the afore- 
said edge, then a fine line drawn on the 
stuff along the edge of the blade; then 
Fig. 30 shows a soelvet mortising chisel. Fig. 31 
is an English duck-bill mortise chisel ; the handle 
is made of wood and fits on the shank. This 
kind of chisel is seldom used now. Fig. 32 is a 
framing chisel, and Fig. 33 is a gouge. Fig. 34 
shows a mallet. This is used to strike the handle 
of the chisel with when making a mortise; some- 
times mallets are made with 'a square head and 
oval handle. Fig. 35 shows a mortise gauge of 
the cheaper sort. This can be made to do exact 
work if everything is tight about it. 
