chosen should be as thin as possible, and quite free from scratches,
bubbles, or flaws of any kind whatever. Remember that a piece of the
finest hair which may well be overlooked upon the slide itself, will
appear on the screen as a huge snake. In like manner a tiny bubble in
the glass is magnified into a blemish the size of a soup-plate. Glass
presents a very difficult surface to draw or paint upon, particularly
if water-colours are employed, but by coating it with a transparent
medium in the first instance the difficulty is much reduced. A film
of plain collodion will, when dry, give a surface that can be easily
sketched upon with a fine pen and Indian ink. The sketch so made can
afterwards be filled in with water-colour, tempered with prepared
ox-gall, and taking care that the colours used are those which are
naturally transparent. Prussian blue, indigo, lake, the madders,
gamboge, burnt and raw Sienna, Vandyke brown, are all transparent
pigments, and will answer every purpose. Mixed with one another in
the manner detailed in any manual of water-colour painting, greens,
purples, and all secondary and tertiary tints are readily obtainable.
Another method, and an easier one, for producing lantern slides was
introduced some years ago by the Rev. W. H. Dallinger; and although the
author of the method intended it for drawings of microscopic subjects
only, and with that idea brought it before the notice of the Royal
Microscopical Society, it will be readily seen that it is adapted to
all manner of lantern pictures. This method is best described in its
inventor’s own words: ‘On finely ground glass drawing with a black-lead
pencil is as easy as drawing upon cardboard. I get squares of glass
to suit the size of my lantern carefully ground on one side like the
focusing-glass of a camera.’ The author goes on to describe how, by
sketching upon the finely ground surface with a well-pointed hard
pencil--HH or HHH--and shading with a softer one, such as HB, capital
effects can be obtained. ‘If it be necessary to put in colour it may be
done, cleanly and carefully over the shading; thus one layer of colour
suffices. Now, of course, although we have a perfect drawing of the
object, with all the detail accurately given, it is not a transparency.
But we can easily make it one. Thin some good pale Canada balsam with
benzine to about the consistency of cream, and simply float it over
the ground surface of your glass; pour off until the drop comes very
sluggishly. Then reverse the glass so that the corner from which the
balsam was flowing off be placed upwards. Let the return flow reach
about the middle; then reverse it again, and move it in several
directions to get the balsam level. This may be done with a very little
practice, so that the surface shall be undistinguishable from glass. We
have now a perfect transparency. All that is required is twenty-four
hours for hardening (keeping the glass level), and then another square
of glass fastened on to it by strips of paper at the edges, with small
pieces of card at the corners to prevent contact, and it makes an
admirable lantern transparency.’
A hint about giving a fine grain to glass will not be out of place.
Upon a perfectly flat and firm table lay a piece of glass say six
and a half inches square, for this size can afterwards be cut across
into four lantern pictures. A sheet of wet blotting-paper under the
glass will keep it steady. Now pour upon its surface a mixture of
flour-emery and water. Place another piece of glass above, and work it
round with a circular motion, constantly spooning up the mud formed
by the emery and water, and which oozes out between the glasses,
and replacing it between them. In a short time both glasses will be
beautifully ground on the surfaces which have been rubbed together. A
moment’s consideration will show that the ground effect is produced
by the surface being broken up into innumerable tiny pits, each one
of which scatters the light. By Mr. Dallinger’s method of filling up
these pits with a glassy medium like Canada balsam, the glass is once
more presented with a flat surface, and therefore becomes once more
transparent.
By whatever means the picture is produced the operator should have a
glass transparent easel to work upon placed at an angle of forty-five
degrees, with a sheet of paper underneath it to throw the light up
through the glass he is drawing upon. A good easel can be made of a
small frame--that belonging to a twopenny slate will do--attached to
a base-board, and supported on each side by struts. A ledge of wood
screwed across the frame makes a convenient support for the picture.
The annexed cut will sufficiently explain the arrangements described.
[Illustration: FIG. 6.
Glass easel.]
And now a word or two about mounting the picture. As Mr. Dallinger
points out, a cover-glass should be provided, but it should be
prevented from actually touching the painted surface. This is best
brought about by using the masks cut out of black paper, and sold for
the purpose. A mask is inserted between the glasses, after which the
whole is fastened together by pasting a slip of paper round the edges
of the double glass, and turning it over on either side. Gum arabic
with twenty-five per cent. loaf-sugar added, is a good medium by which
to attach paper to glass.
[Illustration: FIG. 7. Masks for lantern slides.]
ON THE COLOURING OF PHOTOGRAPHIC TRANSPARENCIES.
There are many amateur photographers nowadays who can produce fair
transparencies for the lantern, but at the same time there are many
possessors of a lantern who know nothing about the ‘black art.’
Luckily for these, first-class pictures can be bought cheaply, their
average price ranging from eighteenpence to two shillings each.
Any optician’s catalogue will show what an immense variety of
subjects there is to chose from; not only can we obtain landscapes of
nearly every part of the world, but we can purchase figure studies,
copies of various pictures from books, maps, diagrams of scientific
matters--micro-photographs and statuary. These slides if coloured are
double the price of plain ones, and if very well coloured their price
is quadrupled.
It would therefore be serviceable to many if they could learn how to
colour such pictures for their own use, and I give simple directions
how this can be accomplished. At the same time it is only fair to state
that the work is really difficult, and anyone to attain even slight
proficiency in slide-painting must devote a great deal of time and
patience to the subject.
The photographic slide as sold consists of two glasses, one of which
bears the photograph. This is separated from the cover-glass by a paper
mask, the whole being bound round by a fillet of gummed paper. After
carefully cutting round this fillet the two glasses may be separated,
and the one bearing the picture is placed, varnished side upwards, upon
the glass easel, ready for colouring. Some colourists speak in favour
of water-colours for glass-painting, others prefer oil-colours, while
some, I understand, employ both on the same picture. I have tried each
system, and most certainly recommend oil-colours as being both easier
to work with, and doing more satisfactory work into the bargain than
water-colours.
The materials required comprise ordinary oil-colours in tubes, of which
the following are perhaps the most useful that can be employed for the
purpose:
Italian Pink.
Raw Sienna.
Yellow Lake.
Chinese Orange.
Brown Pink.
Prussian Blue.
Indigo.
Neutral Tint.
McGilp.
Brown Madder.
Rose Madder.
Purple Madder.
Crimson Lake.
Burnt Sienna.
Ivory Black.
It is curious to observe that the suitability of these colours for
the particular purpose of glass-painting varies with the method of
manufacture. I find by experience that one maker’s Prussian blue is
better than another’s, while for a suitable crimson lake I have to go
to quite a different shop, and so on.
The brushes used must be of the best, the majority of them being
camel-hair, a few fine sables being kept for special touches. It is
also necessary to provide some good large bushy camel-hair brushes to
be used as softeners.
A flat porcelain palette is better than one of any other material, for
the strength of the tints is seen well, and the surface can easily be
cleaned with a little turpentine. A flexible palette knife must also be
provided.
Dabbers to soften down skies and other flat masses of colour can be
made by wrapping a ball of cotton wool in fine wash-leather. The
leather should be first thoroughly washed with soap and water, and
it will be better if a little of the soap be left in it as it dries,
for this renders it soft and pliant. Both dabbers and brushes should
be kept in a dust-tight box, for dust is the greatest enemy of the
slide-painter.
It will be noticed that the list of colours given includes those only
which are transparent, many others used in ordinary oil-painting being
omitted. It is obvious that opaque colours like Naples yellow or chrome
yellow would simply appear black on the sheet. The tyro who is used to
other methods of painting, and has some idea of the harmony of colours,
will, of course, have an immense advantage over anyone without artistic
knowledge or feeling; and when he has once mastered the technicalities
of the new work, will soon be able to produce passable pictures. The
list of colours given is necessarily limited for the reason already
given, but their number can be increased indefinitely by judicious
blending one with the other. Let me give a few instances.
There is no green in the list given, simply because I do not know of a
good transparent one. But various tints of green suitable for foliage
can be easily made up with the colours named. Prussian blue mixed
with any of the yellows will at once give a crude green, but it will
not be suitable for use without the help of some other tint, such as
burnt Sienna, or one of the reds. Italian pink and indigo make a fine
green. Italian pink, brown madder, and Prussian blue is also another
useful combination. Brown pink, indigo, and Vandyke brown will be found
admirable for the shadows in foliage; indeed, the combinations for this
purpose are endless. Again, there is a difficulty generally found in
obtaining any approach to scarlet. The best I know of is a mixture of
Italian pink, crimson lake, and Chinese orange. For browns, Vandyke
brown, Chinese orange, ivory black, and burnt Sienna, will give any
range of tints, from the coldest to the warmest. The reader will soon
find by experiment the right proportions for mixing these colours to
produce the desired effect, and he will be much assisted in the work
by studying any good manual of water-colour painting. I recommend a
water-colour manual in preference to one dealing with oil-colours,
because the first deals more with transparent tints, which depend for
their effect upon the white ground upon which they are laid. In like
manner a lantern picture depends much upon the white surface upon which
the tints are subsequently exhibited.
Our first attempt at glass-painting shall be an open landscape with
figures in front--and we will suppose that the scene is laid in
Britain. This would seem to some an unimportant point, until they
remember that the skies and atmospheric effects seen in some other
lands would require an altogether different treatment. I once coloured
an Egyptian scene for a friend, and he admired my work, with one
exception. ‘You have given me an English sky,’ he said. The sky will be
the first thing to see to, and we will endeavour to give it a flat tint
of blue slightly darker at the zenith than it is at the horizon. We
squeeze out from its tube a little Prussian blue upon the palette, and
dipping a good-sized camel-hair brush into a small cup of turpentine,
we take up a little of the colour and work it about on the palette
until it seems of the right strength. Before applying it to the glass
we add to it a very small quantity of McGilp medium. Having mixed
this last addition with our brush-load of colour, we can apply it to
the glass, painting it in broad bands from side to side until the sky
is all striped with blue. If the subject comprises a range of distant
hills, let them too partake of the blue tint. When this is done, lay
aside the brush and let the coloured glass rest for a minute, so that
some of the turpentine will dry off. Now proceed to dab it carefully
with one of the leather dabbers. With a very light touch bring the
dabber down over and over again, and avoid anything like a rubbing
action. The movement must be vertical, and not in the least horizontal.
By bearing a little more heavily on the dabber as the horizon is
approached, the tint will be sensibly lightened.
When this sky-colour has been uniformly dabbed in we may proceed to
put in, or rather wipe out, some cloud effects. A little piece of soft
kid wrapped round a pointed pen-holder is a good tool to use for the
purpose, but a leather stump will answer the same end. This part of
the work requires a little judgment and artistic taste. In a picture
full of detail and which only has a small portion of sky exposed, it
is best coloured simply blue. But where there is not much detail in
the landscape, as in the case for instance of a mill on a bleak moor,
the sky can be worked up with great advantage to the general effect.
The clouds are wiped out by a rubbing action combined with a dabbing
movement, so that the edges of the clouds formed remain quite soft. If
they appear too hard they can be corrected by a few gentle dabs with
the top of the finger. Before the leather is laid aside, it may be
employed for wiping off any portions of colour which have accidentally
been placed where they should not be. But if there is water included in
the subject, such as a lake or river, it will when the sky is reflected
in it partake of the same colour, and should be dabbed in at the same
time.
We must now consider how we are going to treat the rest of our
picture. If there is some expanse of foreground it will make the best
contrast with the sky if we use a warm sandy colour. Chinese orange,
raw Sienna, and brown pink mixed in various proportions to suit the
lights and shadows of the picture will give the tint required. At this
stage, too, the middle tints of the composition lying between the sky
and the foreground can also be laid in. These will mostly consist of
subdued greys, made up of Prussian blue, burnt Sienna, purple madder,
and crimson lake. When these tints are all dabbed in, and the whole
picture has been carefully gone over with the leather point, so as to
remove truant colour, the slide may be laid aside to dry. I find it a
good plan to have a tin box containing grooves for this purpose. The
slides when grounded in in the way just described are placed in the
grooves, and the open box is turned towards a fire. In an hour or so
the colours are dry enough for further treatment.
We can now once more view our work on the easel, and most probably
we shall see much to amend. The trees in the middle distance are too
yellow, or too blue. They are easily corrected by a touch of the tint
in which they fail. But at this stage of the painting we must use a
different medium for our colours. We have done with dabbing, and must
now lay the colours on as smoothly as possible with the brush alone.
Canada balsam in turpentine, of the consistence of very thin varnish,
is perhaps the best medium to use. It should be mixed with every colour
as it is taken upon the brush.
The beginner will find some difficulty at first, particularly if
oil-colours are new to him, in keeping his brushes in order. He need
not have a brush for every tint. Let one be kept for skies, but only
two or three others are necessary. When I commence to paint a batch of
pictures I put on my table, after carefully dusting it all over with
a damp cloth, a sheet of newspaper. In the centre stands my easel. On
the left hand my colour-box, and on the right my palette. Close to the
palette is placed a double thickness of clean white tissue paper, and
a small pot of turpentine. When I wish to clean my brush, it is simply
dipped in turpentine, and drawn over the surface of the white paper
until I see that it leaves no trail of colour. By this simple means one
brush can be used for any number of tints, for the cleansing of it does
not occupy more than ten seconds.
It is in the foreground of a picture that the artist must be lavish
with his bright colours. If the figures in the subject will allow of
bright colouring, so much the better; but it must be remembered that if
these colours are not put in with some regard to contrast, their effect
is much diminished, if not altogether lost. Let the painter remember
that the principal colours have their complementary colours, and that
wherever we can place one of these tints against its complementary, we
are bound to have harmony. Thus the complementary of blue is orange; of
red, green; and of yellow, purple. But for further particulars of this
nature, the aforesaid ‘Manual of Water-Colours’ must be studied.
When the picture is apparently finished, it will, most likely, require
some finishing-touches. And here a new tool comes into use, namely,
the etching-needle. Take a pointed piece of wood, about the size of a
penholder, and bind upon it, by means of waxed thread, a good strong
sewing-needle, leaving not more than a quarter of an inch of the
point exposed. A few judicious touches with this needle will make a
vast difference in the effect of a picture, but anything like coarse
scratching must be avoided. The beginner will do well to view his work
in the lantern as it gradually progresses, for what may look very well
on the easel, will look very different when all its imperfections
are magnified on the screen. The art of slide-painting is one which
requires constant care and practice before anything like proficiency is
attained.
In case some of my readers should be well acquainted with the
use of water-colours, and may be deterred from trying the art of
glass-painting because oils only are recommended for the work, I will
briefly describe how water-colours are utilized for slide-painting.
At the same time, I hold to my previously expressed opinion, that
oil-colours are the more suitable pigments to use.
The varnished surface of a glass picture does not take kindly to
water-colour, and as the brush is applied to it there is a repellent
action which would make the painter despair if some means were not at
hand to obviate the difficulty. By mixing each colour with a certain
proportion of prepared ox-gall the difficulty vanishes, and it is a
wise precaution to rub a little ox-gall and water over the surface of
the picture by means of a tuft of cotton wool, before any colour is
applied at all.
The same transparent colours as those recommended for oil-painting may
be employed, besides a few more transparent tints which are commonly
not ground up in oil. But the dabbers are of a different description.
Procure two or three good thick camel-hair brushes, and cut the hair
off straight with a pair of scissors, so as to leave the ends of the
hairs like a flat stump. Now carefully turn the brush round and round
in the flame of a spirit lamp, or candle, so as to just singe the
point of each hair. When this is done, rub the ends of the hair on the
finest glass-paper until every trace of singeing has disappeared. This
treatment will leave the brush with a flat woolly head like a mop,
which makes an excellent dabber.
When the sky-colour has been applied as evenly as possible, and has
been allowed to dry, the surface may be worked over with the dabber.
But, before doing this, gently breathe over the colour. The dabber will
remove little particles of the pigment, and will reduce the general
strength of the tint, so that this loss should be provided for when
the colour is first applied. Clouds, etc., can be wiped out with the
leather, after the breathing operation, and in many other respects the
two modes of colouring agree.
When the general tints have been laid in, the colours may receive a
coat of mastic varnish, and this again can be worked over with colour
to strengthen those tints which may require it. The varnish also
confers a transparency upon the tints that they do not possess without
it.
SHOWING SOLID & OPAQUE OBJECTS ON THE LANTERN SCREEN.
Those who are familiar with the working of the microscope know that
the objects which are employed in that instrument can be viewed in
two different ways. Transparent preparations have the light thrown
through them by means of the adjustable mirror beneath the stage.
Opaque objects, on the other hand, must have light thrown upon them
from above, and this is managed by means of a separate condensing lens.
For the magic lantern, transparent pictures are almost wholly employed;
but there is a means of utilizing paper prints, photographic _cartes de
visite_, and a certain limited number of solid objects, so that they
may be shown in an enlarged form on the sheet. The effect is not so
bright as when transparencies are employed, for a large proportion of
the available light is absorbed in the operation; but there are many
who would sacrifice a good deal in the way of effect, for the undoubted
advantage of being able to utilize the contents of their albums, etc.
[Illustration: FIG. 8. Ground-plan of Chadburn’s Opaque Lantern.
_p_, Picture; _c_, Condenser; _l_, Light; _r_, Reflector; _o_,
Objective.]
The first instrument which was constructed to accomplish this end is
known as Chadburn’s lantern; and, as will be seen from the annexed
diagram, it differs very much from the ordinary form of magic lantern.
From what has been already said concerning the loss of light, it will
be evident that a powerful luminant is a matter of prime consideration.
A good oil-lantern will do the work--but not so well as the lime-jet.
The luminous face of the lime, instead of being turned towards the
optical system, is opposite a concave reflector placed at the back of
the lantern. From this the light is reflected towards the condenser,
which condenser concentrates the light obliquely upon the object. The
picture or object is contained in a kind of box joined to the main
lantern, and which holds immediately opposite the illuminated picture
the lens for projecting its image upon the screen. This pioneer form
of opaque lantern has been superseded by the instrument called the
Aphengescope. This can be purchased now of most opticians. Virtually it
consists of the front chamber of Chadburn’s lantern constructed to fit
on to the front of any ordinary oil or lime-lit lantern.
The aphengescope can be used for showing woodcuts, paper photographs,
printed and written matter of any kind, so long as the space covered is
within the size of the instrument. Thus any caricatures from our comic
publications could be pasted on card, and enlarged by its means. But it
will be readily observed that this class of subjects, if photographed
as transparent positives and used in the ordinary lantern, can be shown
far better. The principal use of the aphengescope is to show solid
objects which cannot by any possibility be shown enlarged without its
help.
Let us suppose, for instance, that it is desired by some collector
to show his friends a cabinet of coins and medals. Such objects are
so bright in themselves that they are admirably adapted to this
instrument. Their form, colour, and minute markings are faithfully
reproduced; whilst the raised portions catch the reflected light
in such a way as to make the images look as solid as the objects
themselves. At the Polytechnic Institution, a lecture upon the
invention of the watch, and its gradual development, was beautifully
illustrated by the opaque lantern. First came the different parts of
the watch, and then the varied movements. It was most curious and
instructive to see the wheels and springs all in movement upon the
screen.
There are also many natural things which can be shown by the same
means. A freshly opened oyster makes a very remarkable object. A
still more curious effect is obtained by concentrating the light
upon a freshly cut orange or lemon. When the fruit is squeezed, the
pips and juice appear to fly upwards; for, of course, everything is
shown upside down, as in the ordinary lantern. The opaque lantern was
once introduced into a court of law in America, as a witness for the
prosecution in a case of forgery. The following is a condensed account
of the occurrence, taken from a New York paper: