T^HE YOUNG SCIENTIST. 
71 
useful and honorable line of occupation 
for leisure hours, in which his labor shall 
be really valuable, if duly registered; 
. . those who possess good instru- 
ments, have a field absolutely boundless 
for their exertions."— jF>'0??i advance sheets 
of Webb's Celestial Objects for Common 
Telescopes. ^ ^ ^ 
Etching on Copper. 
SINCE the publication of the articles on 
Collodio-Etching, we have had several 
inquiries in regard to the method of etch- 
ing on copper. The simplest and most 
thorough directions to amateurs for pur- 
suing this interesting art are those by E. 
Scott Burn, which we here reproduce. 
The art of etching is not difficult to ac- 
quire, the principal requisite being the 
ability on the part of the operator to draw 
freely and accurately. 
It will be our endeavor to describe the 
process in such a cleat manner as to ena- 
Ible any one who has a knowledge of draw- 
ing to make a successful plate. 
Etching enables us to produce lines on a 
metal plate capable of throwing off an im- 
pression. To effect this, it is necessary to 
cover the plate with a preparation which 
will resist acid. If on such a preparation 
acid is applied, it will not act on the cop- 
per ; but if a scratch is made through the 
preparation, and the acid thereafter ap- 
plied, it will eat into a line, deeper or 
shallower, according to the length of time 
the acid is allowed to remain. The metal 
generally used for etching is copper, the 
plates of which should be carefully pre- 
pared. 
Etching is not meant, as some suppose, 
to be an easy method of imitating line- 
engraving ; in fact, the grand distinction 
between the two styles is this, that in line- 
engraving the lines, however beautiful in 
effect, are produced by means more or less 
mechanical, while in etching, the lines and 
effect are put in with a facility of drawing 
and freedom of touch which is displayed 
in free pencil-sketching on paper. In 
etching, the needle and the aquafortis are 
the only assistants ; the graver is seldom 
required, and the oftener it is used, the 
stiffer the drawing becomes, and more re- 
moved from that exquisite freedom and 
ease which is the characteristic of a true 
etching, representing, as it does, or ought 
to do, the ease with which the original 
design or subject is transferred to the 
paper or the canvass. 
First, as to the "etching ground " This 
is a preparation of wax, asphaltum, etc., 
the following being a favorite recipe: 
Take of beeswax and asphalt two parts 
each ; Burgundy pitch and black pitch 1 
part each. Melt the wax and the pitch 
in an earthen vessel, and add the asphalt 
by degrees in fine powder. Expose to heat 
until a drop, which has been cooled, breaks 
by bending back and forth two or three 
times in the fingers. As much depends 
on the quality of the ground, the expense 
not being great, we would recommend our 
readers to purchase it ready made. It is 
sold by most of the dealers in engravers' 
tools, etc. In order to prevent any grit 
coming to the plate, it is better to inclose 
the ground in silk for the purpose of fil- 
tering any imperfection. 
The following tools and imi^lements are 
necessary : The " dabber," which is com- 
posed of silk of a fine texture, and evenly 
stuffed with wool until it assumes the form 
required (Eig. 1). It is necessary to place 
Fig. 1. 
a circular piece of card at the top of the 
dabber, immediately below the handle. 
The "etching-point," the "graver," the 
"scraper," the "burnisher," and the 
" hand-vice." An etching table must also 
be provided, with the following acces- 
sories : A copper plate on which the sub- 
ject is to be etched, with support and 
ruler. Looking-glass for the purpose of 
reversing drawing. Tissue paper strained 
on a thin frame to prevent the light from 
glistening too much on the plate. Black 
varnish for stopping out scratches and 
such tints as are "bit " sufficiently dark. 
Nitric acid. Water. Spirit of turpentine. 
An ordinary china or earthenware plate 
and pencils for mixing the varnish. 
