THE YOUNG 
made to admit the blade of the saw to pass 
through. 
If the pupil is a i)retty fair hand to draw, 
he may be able to make his own designs, 
if not, it is better to purchase them in 
sheets, as they can be obtained at very 
reasonable rates ; and where it is desirable 
to preserve any particular design, it may 
be done by first pasting the original de- 
sign on a thin piece of stuff, then taking 
another piece of thin stuff and inserting a 
flat piece of zinc between them and sawing 
all three together, being very careful to 
follow the lines of the design closely, for 
any defect in the sawing will be a perma- 
nent one in the pattern. There will be no 
difficulty in cutting the zinc ; use a No. 3 
;saw, feed slowly and you will be aston- 
ished at the result. This is the best way 
I know of for saving a valuable pattern, as 
the zinc will not break or change its shape. 
When the sawing is finished, there will in 
all probability be a few rough edges and 
crooked corners ; to remedy these use your 
files and sand paper, being careful not to 
file down any of the angles. The under 
edges will be somewhat ragged, but a 
proper application of sand paper will 
make them smooth. 
The next thing will be to put the work 
together, which, with some young folks, is 
a more difQcult job than to saw it, but any 
one having the smallest amount of con- 
:structive ability, will be able to put the 
work together without much trouble. If 
the bracket is intended to carry books or 
other heavy articles, it is always better to 
put it together with screws and glue ; if, 
however, light articles only are to be placed 
on the shelf, brads and glue will be all 
that will be required to fasten on the shelf 
and sustaining bracket. The shelf and 
sustaining bracket should always be thick 
enough to admit of small screws being- 
used in them to fasten them together. 
Fig. 18 is a more elaborate bracket than 
the preceding one and will require more 
care in cutting, but the pupil, after satis- 
factorily finishing the bracket shown at 
Fig. 17, can safely be trusted to saw this or 
-any similar one. Further examples of 
brackets are unnecessary, as these cuts 
are too small to be of much service to the 
amateur without being enlarged ; and are 
SCIENTIST. 141 
only intended to aid him in choosing such 
designs as may be useful to him in mas- 
tering the saw. 
It is supposed now, that the pupil is 
fully competent to cut any kind of bracket, 
therefore, it is time he should try his hand 
Fig. 18. 
at something else ; so at Fig. 19 he is 
shown a small frame for a photograph, 
which is to be cut in holly or walnut ; it is 
Fig. 19. 
very neat and will try the patience and in- 
genuity of the sawyer, but perseverance 
and love of the work will soon overcome 
any little difficulty that may occur. 
In the next issue I will take up the sub- 
ject of inlaying, as the pupil is now suffi- 
ciently advanced to make an attempt, with 
fair chances of success, of doing some 
handsome work in this department. 
Straight Edges. 
PEEFECT accuracy of outlines is of the 
highest importance in the construc- 
tion of all machines and parts of machines. 
The amount of care requisite to the pro 
duction of a good straight edge, or sur- 
face plate, is very great. The means by 
which this accuracy is attained are some- 
what as follows : 
Three pieces of mahogany, or other hard 
wood, about three feet long by a quarter 
inch thick, are planed up as truly as pos- 
sible, the planed surfaces of all three being 
from time to time applied to one another, 
