THE YOUNG SCIENTIST. 
75 
with positive electricity. By repeating 
this operation the charge is increased 
<3ach time. As the paper does not lose its 
electricity, it may be used several times 
in succession, until the apparatus is fully 
charged. 
A very pretty effect may be produced by 
pasting narrow strips of tinfoil on a pane 
of glass, as in the figure, and cutting 
.across them so as to make the breaks in 
the form of letters or words. By connect- 
ing one end with the ground, and the other 
end with the electropliorus, by means of 
wires or chains, a spark will be produced 
at each break, thus forming the word in 
letters of light. To get good results from 
these experiments everything should be 
warm and dry. Kenneth Haetley. 
A Home-Made Printing-Press. 
BY ONE or OUE ' ' SUBS. ' ' 
EAELY two years ago I made a 
small printing-press from which 
I have had good service. The 
following is a description. A 
smaller one can be made by observing 
the proportions. 
From the grocery-store I obtained two 
lemon boxes, having at each end and in 
the middle a thick piece of board, which 
were of hard, fine-grained wood. The 
boards I chose were well-seasoned and 
without knot or crack, and I planed them 
■down smooth and true to f in. thick X 85 
long X 6| wide. I have two chases made 
of strips of this same wood. One is 6X4 ; 
the other 3hX^l The strips are cut the 
desired length, 2 in. deep X i thick. The 
^ m 
Fig. 1. 
Fig. 2. 
ends are dove-tailed, and, where practic- 
able, put all around some brass to give 
strength. At the top insert two screws, 
to hold the type in place. 
Now take one of the smooth boards (a), 
in the middle of which you screw on the 
chase by means of four small plates of 
brass, two on either side of chase, as in 
Fig. 1. At the back of this board (a) 
screw a piece of wood the same length 
and thickness as the board, and I2 in. 
wide at middle, as at Fig. 2. 
Through the middle of this piece runs a 
round steel or iron pin i diameter. 
Make two uprights, 11 in. high, | thick, 
62 wide at base, 5 wide at top, shaped like 
Fig. 3. Put these uprights in a grooved 
board 19 in. long, 85 
wide, 1 thick. Place 
uprights two inches 
apart (inside measure- 
ment) in the grooves, 
which are to be k in. in 
depth, and so that the 
uprights will fit in 
them tightly, and 
y, « screw them under- 
/ \ neath the base board, 
r \ Between the uprights, 
— ^ in the middle, put a 
piece of wood to keep 
them in position. This 
done, adjust the board (a) i?i such a way 
that the middle will rest on the top of the 
Fig. 3. 
Fig. 4. Fig. 5. 
uprights, by means of the pin run- 
ning through the jiiece of wood at the 
back. Hold the ends of pin in posi- 
