of nitric acid, diluted with an equal quantity of water, add nearly an
ounce of mercury, or as much as the acid will dissolve. When this is
dissolved, add to the solution, gradually, half an ounce of sulphuric
acid; this will precipitate the mercury in the form of a white powder;
when this has subsided, pour off the acid and add clear water; thus
wash the powder from the acid, then pour off the water, and while the
precipitate is moist, (or if it be suffered to dry, it may be again
moistened with water,) rub it over the tin with a piece of glove
leather.--Then wash the tin with water, and when it is dry, rub it
pretty hard with a piece of fine woollen cloth; it will resemble
polished silver.
44. TO GIVE TIN A CHANGEABLE CRYSTALLINE APPEARANCE.--Cleanse the tin
by washing it with warm soap and water, and rinse it in clear water.
Then heat the tin to the temperature of bare sufferance to the hand,
and pour on it, or apply with a brush or sponge, a mixture of one
ounce of muriatic acid, with one fourth of an ounce of sulphuric acid,
and two ounces of water; then immediately wash the tin in clear water.
Another method is, to apply in the same manner a solution of two
ounces of muriate of soda, in four ounces of water, with one ounce of
nitric acid. In either case, if the crystalline figures are not bold
enough, the operation may be repeated. If a very small figure is
required, the tin may be heated nearly to flowing, and plunged into
cold water, slightly acidulated with nitric and muriatic acids. If a
little solder is drawn over the tin with a hot iron or copper, in such
manner as to form a cross, or circle, and the opposite side of the tin
be afterwards crystallized, it will have a beautiful effect.
45. TO MAKE A GOLD COLOURED VARNISH FOR TIN.--To half a pint of
alcohol, in a flask, add one ounce of gum-shellac, and half an ounce
of turmeric, both in powder; set the flask in a warm place, frequently
shaking it, for twelve hours or more; then filter or strain off the
liquor, which may be occasionally diluted with new rum.--If a colour
is required resembling dutch gold, a small quantity of dragon's blood
may be added, or substituted in the place of turmeric.--When this
varnish is used, it must be applied to the work freely and flowing,
and must not be brushed or rubbed while it is drying. One or more
coats of this varnish (or laquer as it is sometimes called) may be
laid on the work, as the colour is required to be deeper or lighter.
_Note._--To make a rose coloured varnish, proceed as above directed,
only substitute one-fourth of an ounce of the best lake, finely
ground, in the place of turmeric. A transparent blue varnish may also
be made by means of prussian blue; and purple or green, by adding a
little blue to the gold, or rose coloured varnishes. These laquers are
frequently employed for washing silver bronzed ornaments, to give them
the appearance of gold or copper.
46. TO MAKE SHELLAC VARNISH FOR JAPANNING.--To one quart of the best
alcohol, add half a pound of the thinnest and most transparent
gum-shellac; mix and shake these together, and let them stand in a
warm place for two or three days; then strain the varnish through a
fine flannel, and bottle it. Shellac varnish is used for japanning
lamps, tea trays, &c. Any of the colours commonly used for oil
painting, may be ground in this varnish and should be applied to the
work with a smooth brush, and in a warm place; and the work to be
japanned, should be perfectly dry and warm. _Note._--Most of the
writers on the subject of japanning, have recommended seed-lac
varnish; but it is a fact, though not so generally known as it ought
to be, that shellac and seed-lac are the same substance; the only
difference is, that shellac is in a more clarified and refined state,
than that which is called seed-lac.
47. TO MAKE THE BEST COPAL VARNISH.--Take one pound of gum-copal, and
melt in a flask over a brisk fire of charcoal; at the same time in
another flask, boil, or heat to the point of boiling, one pint of
linseed oil; as soon as the gum is melted, take it from the fire, and
add the hot oil in small quantities, at the same time stirring or
shaking it till they are thoroughly incorporated. Allow the mixture to
cool below the boiling point of water, and then add nearly a quart of
spirits of turpentine;--cork the flask slightly, and expose it for a
few days to the rays of the sun, which will make it work more smooth
and shining. If a larger quantity is to be made, a copper boiler, that
is small at the top will answer to melt the gum in. For ordinary or
coarse work, a larger proportion of oil and a little rosin may be
added. If oil is used in which red lead and litharge (in the
proportion of half a pound of each to a gallon of oil) have been
previously boiled, the varnish will the sooner dry.
48. TO MAKE A SPIRIT VARNISH FOR PICTURES AND FANCY BOXES.--To a pint
of alcohol, in a flask, add four ounces of gum-mastic, and one ounce
of gum-sandarac, both in powder; expose the mixture to a gentle heat,
sufficient to produce a slight ebulition for a few minutes, frequently
shaking it, and the gums will be dissolved; strain the varnish through
a fine flannel, bottle and cork it. Some recommend the addition of
venice turpentine, by means of which, a small quantity of gum-copal,
finely powdered, may also be dissolved, but as venice turpentine
contains a portion of spirits of turpentine, it renders the varnish
too penetrating for many purposes; and even the gum-sandarac may be
omitted without any essential disadvantage. This varnish should be a
little warm when used.
49. TO MAKE ELASTIC VARNISH FOR UMBRELLAS, OR HAT CASES.--To a pint of
spirits of turpentine, in a flask, add one ounce of gum-elastic, cut
into very small pieces; put in the cork slightly and set the flask in
a warm place, where the heat may not be equal to that of boiling
water, till the gum-elastic is dissolved, which may be effected in
four or five hours. Then strain the solution through a strong linen or
cotton cloth, and add half a pint of boiled linseed oil. _Note._--A
larger proportion of gum-elastic may be dissolved, and a less quantity
of oil added, by which means the varnish will be more elastic, but
will not have so smooth and permanent a gloss.
50. TO VARNISH MAPS AND PICTURES.--Take a piece of linen, or cotton
cambric, rather larger than the map or picture to be varnished, and
draw it straight upon a frame of convenient size, and confine it at
the edges by small tacks or nails. Lay a thin coat of fine rye flour
paste on this, and on the back of the paper that is to be varnished;
lay the paper on the cambric and press them together till the paper
adheres firmly in every part. When this is dry, give the face of the
print two or three coats of a strong solution of gum-arabic in water,
allowing each sufficient time to become perfectly dry. This sizing
must be applied with a large smooth brush, and must be spread over the
work very quickly, and with as little brushing as possible.
Afterwards, give the work one or more coats of the varnish described
at 48. _Note._--Very small prints may not require to be pasted on
cambric; and if the paper be very thick, the varnish may be applied
without the previous sizing. Ising-glass, (which may be readily
dissolved in boiling water) is sometimes added to the gum-arabic, and
increases the strength of the sizing, but is somewhat less transparent
than pure gum-arabic. A more simple method of varnishing prints, is to
size them with a solution of loaf sugar, and finish with a solution of
rosin in spirits of turpentine.
51. TO MAKE BRUNSWICK BLACKING FOR PICTURE GLASSES.--Take one pound of
gum-asphaltum and melt it over a slow fire; then take it from the fire
and add spirits of turpentine in small quantities, stirring it briskly
till it is of the consistence of varnish. As there is some danger of
its taking fire when the spirits of turpentine is added, it may be
well to be provided with a piece of wet flannel, to throw over it if
that should happen. When it is nearly cold, strain it through a
flannel, and bottle it for use. This blacking is used for bordering
picture glasses, and is probably the most perfect black in nature. It
is water proof and dries very quick.
52. TO MAKE A PRINT APPEAR ON A GOLD GROUND.--Dilute venice turpentine
with spirits of turpentine till it works freely with a camel-hair
pencil; lay a coat of this varnish on any part of a print or picture,
observing to keep the pencil within the lines, that the varnish may
not spread beyond. Then lay a coat of the varnish on the same part of
the back of the paper and lay on a leaf of gold over the varnished
part; press down the gold very gently with cotton, and the varnish
having rendered the paper transparent, the face of the picture will
appear as if those parts were printed in gold. By this varnish (which
is less liable to spread in the paper than oil) pictures may be so
prepared, that the colours of various parts of them, may be varied and
changed at pleasure, by placing pieces of silk or paper of different
colours on the back of them.
53. BEST METHOD OF TRACING OR COPYING A PICTURE.--Perhaps the most
simple method of copying the outlines of a picture, is to place the
picture against a window, with the paper over it, on which the copy is
to be drawn; the principal lines of the picture will be seen through
the other paper, and may readily be traced with a lead pencil. But the
usual manner of copying, in landscape painting, and which will answer
for pictures of any size, is to rub over the back of the picture with
plumbago, or red ochre; then lay the picture on the ground that is to
receive the copy, and trace the lines with a smooth pointed steel, or
piece of hard wood. The ground will thus be very accurately and
distinctly marked, by the plumbago or ochre adhering to the ground in
the lines that are traced. When several copies are to be taken from
the same pattern, (which frequently occurs in ornamental painting,)
the outlines of the first copy may be perforated with some pointed
instrument, so that being laid on the other grounds that are to
receive the copies, and brushed over with a little fine dry whiting,
or red ochre, (as the case may require) the whiting or ochre will
penetrate the perforated lines of the pattern, and thus mark the
ground on which it is laid.
54. THE CONSTRUCTION AND USE OF A COPYING MACHINE.--Take two strips of
wood, which may be about three feet long, one inch wide, and
one-fourth of an inch thick; lay them on a table, parallel to each
other, and eighteen inches apart. Across these, lay three other
strips, which must be eighteen inches long, that each end of each
piece may rest on one of the longer strips. Two of these must lie
across the opposite ends of the longer pieces, and the other across
the centre, thus forming two squares. Drive a pin through the ends of
the short pieces, or confine them by rivets to the others, but not so
as to prevent their playing circularly on the rivets. Then drive a pin
or pivot through the centre of the middle cross-bar into the table, or
board on which the work lies. In one end of one of the long strips
(which may project a little over the cross-bar) fix a lead pencil,
with the point downward, so that it may bear lightly on the board; and
under this pencil, place the paper that is to receive the copy. And in
the opposite end of the other piece, fix a smooth iron point, in a
manner similar to that of the pencil, and under this point place the
picture that is to be copied. Then with the iron point, carefully
trace the lines of the picture, and the pencil in the opposite corner
will move in a transverse direction, and draw the same picture very
accurately on the other paper. If you fix the pencil half way between
its former place and the middle cross-bar, and remove the pivot to a
point that is directly in a line with the pencil and the iron point,
it will give a copy in exact proportion, but only one fourth part as
large as the picture that is copied. Thus the copy may be decreased or
increased to any size, and still retain its regular proportions. In
this manner, painting on wood or canvas may be copied, which could not
readily be done in any other way.
55. TO PRODUCE THE EXACT LIKENESS OF ANY OBJECT, INSTANTLY ON
PAPER.--This may be readily effected by laying the paper on a table,
and holding a double convex lens (a common sun-glass) over it, and
then placing a mirror over the lens, in an oblique position so as to
face partly downward, and partly towards the object that is to be
represented. The rays of light passing from the object to the mirror,
will be reflected downward through the lens, and produce the likeness
of the object in full colours on the paper. This experiment may be
easily made in the evening, by reflecting the flame of a candle in
this manner, which will appear very brilliant on the paper. But in
order to render the reflection of an object distinctly visible by day
light, it may be requisite to exclude nearly all the light from the
paper, except what falls through the lens. In all cases, the lens must
be placed at a distance above the paper, according to its focus, or
the distance at which it would contract the rays of the sun to the
smallest point. A very convenient camera obscura, for drawing
landscapes, or even portraits may be constructed as follows: Make a
box of boards, in the form of a regular cube, being one foot in
length, breadth and height; bore a hole of one inch diameter, through
the centre of the top; and on this, fix a double convex lens, the
focus of which must reach the bottom of the box. Make an aperture of
about six inches in length, and one in breadth, through one side of
the box at the top, by shaving off, or hollowing the edge in such
manner that when you put your face to the aperture to look into the
box, it will exclude all the light except what falls through the lens.
Make a hole through each end of the box, near the bottom, large enough
to put in the hands, with paper and pencil. On the top of the box, on
the right and left sides of the lens, fix two pieces of boards, which
may be about four inches high, eight inches long, and three inches
distant from each other. Between these boards, fix a piece of looking
glass, three inches square, and facing from you; the lower edge of the
glass, being near the lens, on the side towards you; and the upper
edge inclining towards you about thirty degrees from a perpendicular.
Directly over, and nearly four inches above the lens, place another
mirror, the centre of which must face directly towards the lower edge
of the first. Cover the glass-box so as to exclude all the light from
the glasses except what falls on them horizontally from objects
directly in front of you, and place a sheet of paper on the bottom of
the box inside. The rays of light, passing from objects in front, will
be reflected from the first mirror to the second, and from the second,
through the lens to the paper, where you will have a perfect
similitude of the objects in view, in full colours, and true
perspective, and may trace them on the paper, with a pencil or pen.
56. COPPER-PLATE ENGRAVING.--For this purpose, provide a plate of
copper, rather larger than the design that is to be engraved, and may
be about one sixteenth of an inch thick; planish by rubbing it, first,
directly length-wise, and afterwards breadth-wise with a piece of
pumice-stone, which may be dipped occasionally in a mixture of one
part nitric acid, with six or seven parts water.--Then wash the copper
with clear water, and rub it with an oil stone that has a plane
surface; and then polish it with a piece of charcoal, that has been
ignited to redness and quenched in cold water. Afterwards burnish the
copper by rubbing it with polished steel. Lay a piece of transparent
paper on the design that is to be engraved, and trace the principal
lines with a lead pencil;--then brush over the copy or tracing with
dry red ochre, and having rubbed the copper plate with a piece of
bees-wax, lay the red side of the tracing on the plate; then with a
smooth iron point, trace the same lines again, that they may thus be
transferred to the plate by means of the red ochre and wax. Take up
the paper and trace the lines on the plate with a needle, thus scoring
the lines slightly on the copper. Then warm the plate and wipe off the
wax, or wash it off with spirits of turpentine, and rub the plate with
fine dry whiting. The next instrument to proceed with is the graver;
consisting of a blade of steel about three inches long, which is fixed
in a convenient handle like an awl. The form of the graver should be
triangular, or between a triangle and lozenge, having two sides plane
and the other round or swelled; and should taper regularly from the
handle to the point, or nearly so, but the point must be ground off
obliquely so that the edge may extend a little farther than the back;
and the edge should rise a little rounding towards the point. It is
very essential that the edge and point of the graver should be kept
very sharp. The manner of holding the graver, is to take the handle
into the hollow of the hand, pressing it with three fingers, on one
side, and the thumb on the other, and extend the fore finger on the
back of the blade towards the point.--The edge of the graver must rest
on the plate, and its motion when cutting must be endwise in all
cases; though there evidently might be a graver constructed, which
might, in some cases, be handled in a manner more similar to that of a
pen or pencil. A graver of a square form may also be requisite, for
cutting large and broad lines occasionally. In proceeding to engrave
the plate, begin with the outlines, observing to press harder or
lighter on the graver, as the lines require to be larger or smaller,
and finish each line with the same motion if possible, without taking
the graver off the plate. Having cut the outlines, proceed to fill up,
and shade the work discretionally, according to the design. It may be
requisite, after part of the work is engraved, to scrape it lightly
with the edge of the graver, to take off any roughness, that may have
been formed on the part engraved. If after finishing the design, any
part appears to have been improperly executed, such parts may be
erased by the burnisher, and may be re-engraved with the requisite
amendments.
57. ETCHING ON COPPER PLATES.--Melt together two ounces of bees-wax,
and one ounce of venice turpentine, and when the wax is melted and
boils, add by small quantities, two ounces of gum-asphaltum, stirring
the mixture briskly at the same time; and when the mixture is well
incorporated, take it from the fire, let it cool a little, and then
pour it into warm water, and by working it with the hands, form it
into balls of about an inch in diameter, and wrap each of them in a
piece of taffety, or thin silk. Then, having prepared and polished a
plate of copper, as directed for copper-plate engraving, warm the
plate sufficiently to melt the balls of wax varnish, and rub one of
them over it, till every part of the polished side is covered with the
varnish; then with a ball of cotton, wrapped or tied up in taffety,
beat every part of the varnished plate gently, while the varnish is
yet flowing, that it may spread the more even and uniformly. Then hold
the plate in a horizontal position, with the varnished side down, and
hold the flame of a wax candle under it, or a small roll of paper that
has been dipped in melted wax, and thus blacken the varnish while the
plate is yet warm enough to keep it in a melted state. When the
varnish has become sufficiently and uniformly black, let the plate
cool, and having drawn the design on transparent paper, rub over the
face of it with chalk; then wipe off most of the chalk with a piece of
flannel, lay the chalked side on the varnish, and trace the lines,
somewhat minutely, with a smooth round pointed needle. Then take up
the paper, and proceed to scoring the lines in the varnish. For this
purpose you must be provided with several needles of different sizes,
and fixed in handles, which may be about four inches long, and nearly
half an inch in diameter, and the needle may project three fourths of
an inch from the handle. Some of these may be ground a little flat on
one side, and others may be round, but taper more abruptly at the
point. These needles may be held, and managed much the same as a pen.
Begin scoring with the out lines, observing to cut completely through
the varnish, but it is not requisite to scratch the copper, except in
making very heavy lines, when it cannot well be avoided. Having
finished scoring the varnish according to the design, fix a border of
wax (composed of two parts bees-wax and one of venice turpentine)
round the work, on the margin of the plate. This border may be about
half an inch high, and must be fixed to the plate while warm. Then
pour on as much nitric acid, diluted with an equal quantity of water,
as the plate with the border will contain. In about fifteen minutes
pour off the acid, and examine whether it has sufficiently corroded
any part of the work; if so, lay a mixture of warm tallow and linseed
oil over such parts with a hair pencil, and again pour on the acid. In
half an hour more the acid may be poured off, and the plate being
warmed, the border may be removed, and the varnish may be wiped off
with a piece of linen cloth;--the plate may then be washed with olive
oil, and cleansed as before with dry fine whiting. _Note_--Different
artists use a variety of different preparations of varnish for the
purpose of etching. In some old recipes, virgin wax, calcined
asphaltum, gum mastic, amber, colophony, greek pitch, burgundy pitch,
black pitch, resin, shoe makers' wax, &c. &c. are mentioned. But it is
believed that the above described varnish, while it is much more
simple, will answer equally as well for young practitioners; and it is
not expected that any will attempt very nice work, without further
information than they could expect to obtain from the sketches in this
little collection.
58. ENGRAVING AND SCRAPING IN MEZZOTINTO.--Having prepared a plate of
copper, proceed to score it so full of lines, cross-lines and diagonal
lines, that when they are filled with ink, the plate may appear quite
black. For this purpose an instrument will be requisite that is
fashioned similar to a chisel, the round or sloping side being scored
or filed near the point, with lines or notches very near to each
other, so as to form a set of sharp uniform teeth at the edge; this
instrument is called a cradle, and should be a little round at the
corners. This cradle must be moved over the plate, in the manner of a
graver, scoring the plate uniformly in various directions. When the
scoring is finished, take a scraper, which may be similar to a knife,
having two edges, and sloping on each side towards the point; with
this, scrape off the roughness of the plate, in such places as is
required to be the lightest in the print; such parts as require to be
shaded partially, may not be scraped so deep, while the points that
are to be the brightest may be burnished quite smooth with the
polished end of a piece of steel, about the size of a large nail, and
some of the heaviest out-lines may be cut with a graver. Thus any
portraits or other figures may be formed on the plate, with due
proportion of light and shade, and will, if properly-managed, give an
impression on paper, equal in elegance to any that might be produced
by other means.
59. ETCHING IN AQUA-TINTA.--Polish the plate of copper, the same as
for engraving; moisten the plate with water and sift on finely
powdered rosin and gum-asphaltum, so as to nearly cover the plate;
then warm the plate sufficient to make the powder adhere, but not to
melt it entirely. Transfer the design to the plate, and cover such
parts as are intended to remain white, with a varnish composed of bees
wax and linseed oil, which may be coloured a very little with black,
and must be applied to the work, while warm, with a camel hair pencil.
Then fix a border of wax round the plate, and pour on diluted nitric
acid. In about one minute, pour off the acid, and wash the plate with
clear water, but without effecting the varnish;--dry the plate, and
apply the varnish to such parts of the design as are intended to have
but a faint shade; then apply the acid for a minute or two longer.
Thus proceed biting in, and stopping out alternately, till every part
of the design has acquired its proper shade. But if any part requires
a darker shade than the ground, the powdered rosin may be removed from
such parts with a scraper. When the plate has become sufficiently
corroded, the varnish may be washed off with oil, or spirits of
turpentine, and the plate may be cleansed with whiting.