Chapter II: Part 2

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.

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.

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.

_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:

‘During the recent trial, it became necessary to show the differences between a genuine signature and an imitation or forgery of the same. For this purpose, there was brought into court a powerful reflecting magic lantern. The room was darkened, and images of the two signatures, enormously magnified, were thrown side by side upon a screen before the judge and jury. The false signature was at once revealed. The illumination of the writing was effected by means of two powerful lime-lights contained within the lantern. The peculiar arrangement of the lights and screen enables the examiner to discover the surface of the paper through the ink, so that patching, shading, or painting of letters becomes evident the instant it is brought under the focus of the lantern. An arrangement of screens, by which the light is cut off alternately from either side of the instrument, discovers any tampering with the surface of the paper, either by scratching or washing by chemicals. (In other words, by throwing the light alternately from either side, the relief caused by the grain of the paper is clearly shown; and any tampering with that relief, by scratching or otherwise, at once becomes apparent.) The instrument, in this case, was of sufficient capacity to view at once two bank-notes placed side by side, and the pictures were of such fineness that there was no difficulty in viewing their smallest details. I fear that the introduction of a magic lantern into an English court of law would be rather too sensational for the ordinary legal mind--particularly as the evidence of an expert, with the help of a microscope, would answer the same end.

Under the name of the Physioscope, an immense opaque lantern was exhibited some years back in London. The object magnified on the sheet was the human face, and a correcting lens was included in the apparatus, so that the face was seen right way up. It was always rather an unhappy face, for the individual who lent his countenance to the transaction had on either side of him, and within a few inches of his cheeks, a very powerful lime-light, the heat and glare from which were sufficient to render anyone uncomfortable who was not a salamander.

THE LANTERN MICROSCOPE.

Of late years it has become possible to take very beautiful photographs of microscopic objects, which, when used as lantern-slides, give a very fine effect. Numerous slides of this character may now be purchased, which cover a vast field of microscopic knowledge, and many will be content with what they can thus obtain. But there is another class of workers who, perhaps possessing a large number of microscopic slides, will be glad to utilize them for the lantern, so that they are no longer limited to the individual eye. For these the lantern microscope, which will screw in front of the lantern in place of the usual optical system, is a most useful instrument. Different makers advertise in their catalogues lantern microscopes which range in price from twenty-five shillings to as many guineas. And it recently came to my knowledge that a well-known London optician has undertaken the construction of a few of these instruments at the price of £150 each. The amateur lanternist will, therefore, have some difficulty in deciding what he ought to pay for such an instrument. And it is most difficult to advise him on that point. His best plan is, perhaps, to see for himself what the makers can offer him, and, if possible, to seek a trial of the instrument before he purchases it.

The lantern microscope is a modification of the old solar microscope--an instrument which could be screwed against a hole in the shutter of a darkened room--and which had a mirror outside which projected a beam of sunlight through it. The objective lenses were uncorrected, and small in aperture, so that the instrument was far from being a perfect one. But the intensity of the solar light covered many objectionable features, and it was possible to get some astonishing effects with the contrivance. But sunlight is such an uncertain commodity in our climate that, when the lime-light came into prominence, the old solar microscope was forgotten in favour of that which depended upon a more constant, if a far less intense, light source.

The great difficulty to overcome in the lantern microscope is to get the light sufficiently intense to well illuminate the objects. The aperture of a microscope objective, even of low power, is so small, that, when the pencil of light which it emits is spread over a screen, the light is so attenuated that the details of the object are difficult to make out. In the near future, when we are promised that electricity shall be laid on to our homes, as gas is now supplied to us, the difficulty will disappear, for the electric-arc light is many times more intense than the most powerful lime-jet.

Having obtained a lantern microscope, the next thing to consider is the class of objects which can best be shown with it. To help the reader in determining this point, I will now give a kind of sketch of a popular lecture to accompany an exhibition of the instrument.

Such a lecture might usefully commence with a brief description of the microscope: its history, and how, in its improved form, it has opened up a world of minute life, of which our forefathers could have had no conception. We might then put forward a few remarks as to the adaptation of the microscope to the oxyhydrogen lantern, and point out how by its aid a number of persons can at the same time see what, in an ordinary microscope, is visible to only one person. So much by way of introduction.

We might next enlarge upon the circumstance that the contents of the world have been classified into three general divisions--popularly known as the three kingdoms of Nature: the Mineral Kingdom, the Vegetable Kingdom, and the Animal Kingdom. Show how one is dependent upon the other, and the difficulty in many cases of drawing a line to separate the minute organisms of the Animal Kingdom from those of the Vegetable World. Numerous examples from the lower forms of life may be quoted to illustrate this. Now show and explain subjects from each of the three divisions, taking the minerals first. Define a mineral, and show how they crystallize in definite forms. Illustrate the process of crystallization by putting a drop of a saturated solution of sal-ammoniac on a slip of glass, and spreading it over with a brush. Such a glass placed in the microscope will, as it dries, become covered with branches of crystals, which seem to grow and strike out in various directions on the sheet in a truly marvellous manner. Sections of various minerals may next be shown, finishing with sections of coal. In pointing out the origin of coal from plants, we may easily drift into the next division of our subject--the Vegetable Kingdom.

Here we have indeed a wide field to illustrate. Commencing from the simple cell, as exhibited, for instance, in a bit of so-called green mould, and arriving gradually at sections of different stems of plants (which by the way form most beautiful objects on the screen), sections of different woods, parts of flowers, etc. From these it will be easy to step over the indistinct boundary-line which separates us from the Animal World. Here we can commence with the lowest organisms; next show the living inhabitants of our ponds and ditches. Arrive at the Insect World, and show the generally unfamiliar parts of familiar insects--bees, wasps, flies, etc. We can then go higher, and exhibit sections of bone, hair, etc.; finishing with the structure of the human body, so far as it can be indicated by means of the microscope. This is a brief sketch of the kind of entertainment the microscope is able to afford, which can be modified to suit the views of the exhibitor.

MECHANICAL OR MOVING-PICTURES.

The most common form of moveable slide is that known as a ‘comic slip.’ This mechanical contrivance for the amusement of youth is generally of the coarsest execution, and it speaks little for the originality of our slide-producers that the same old things should appear in catalogues year after year with no improvement. The ‘comic slip’ consists of a glass in a wooden frame, with another loose piece of glass which can work backwards and forwards in front of it. This movable glass generally serves as a mere screen to cover something painted underneath it, and it is rubbed over with black varnish so as to be opaque. Thus a gentleman is represented with a nose of the normal size, but as the screen is withdrawn it elongates to an awful extent. Or a woman’s tongue may be graphically, if not elegantly, portrayed in the same manner.

In another class of slide a circular glass is kept in slow rotation in front of the slide proper by means of a rack-work attachment. A common design for this device is a landscape with a windmill in the centre. The sails of the mill are painted on the revolving glass, and can be kept in rotation as long as desired. The chromatrope effect is managed in the same way, only that in this case both glasses are caused to slowly revolve in reverse directions. There are many people who admire chromatropes, and many others who regard them as rather trying to the eyes. Rippling water, the rising or setting of the sun or moon, and astronomical slides illustrative of the movements of the heavenly bodies, are among the subjects which can be well illustrated by mechanical means.

Perhaps the cleverest piece of apparatus ever invented to give the effect of movement by means of a magic lantern is Beale’s choreutoscope. This instrument depends upon the well-known phenomenon common to our eyes, called persistence of vision. The image of anything that we look at is cast upon the retina at the back of the eye by the agency of the crystalline lens, which is placed behind the pupil. So far, the human eye resembles a camera obscura. Persistence of vision means that an image so cast upon the retina remains impressed there for about the eighth part of a second. For this reason we wink continually without knowing it, for the light impression remains with us during the short time that the eye is closed in accomplishing that necessary action. A burnt stick with a red-hot end whirled round and round appears to us like an unbroken circle of fire. The separate drops of rain as they fall from the sky look like streaks of water, and so an artist will represent them in his picture. A quickly moving meteor looks like a long trail of fire for the same reason.

In the choreutoscope we have a very elegant adaptation of the same principle. It consists, in its commercial form, of a slide arrangement that can be placed in any lantern. This contains a narrow strip of glass, with, say, six figures painted upon it, each figure having a different position. A dancing man is a good representative of the rest. By a turn of a handle each figure is brought into view successively, but so rapidly as to give the effect of moving arms and legs. An interceptor or screen runs in front of each figure as the change occurs.

One of the best designs made for this instrument is a dancing skeleton (see annexed cut). In this case the figures are cut stencil-fashion out of very thin brass, and the openings thus cut transmit so much light that the effect is far more brilliant than if the design were executed on glass in the usual manner. The choreutoscope is not only a most amusing contrivance, but it illustrates in a very beautiful manner this optical law called ‘persistence of vision.’

CONCLUDING REMARKS.

The best lantern and the best pictures will not interest an audience unless the entertainer or lecturer is up to his work, and the matter which he conveys is skilfully put together. I believe that lecturing would be far more popular among us had it not been for the numbers of utterly incompetent men who have in past years bored audiences to such an extent that the word ‘lecture’ is to them as a red rag is to a bull. When I say incompetent men, I do not mean uneducated ones; but I mean those who from natural want of voice, and utter ignorance of its management, are generally unfit for public speaking. It seems to be too often conceded that because a man has written a book--or done something else which has brought him before public notice--he is, without any previous knowledge or practice, fit to lecture on the particular subject with which his name is identified. Or his claims to recognition as a lecturer are based upon certain cabalistic letters after his name, which in many cases represent only so many guineas yearly subscribed to those who confer them. Lecturing is an art that can only be acquired successfully by those who have certain qualifications for the work, and among these the foremost is the power of imparting knowledge to others in a common-sense and interesting manner. Luckily for him, the amateur lecturer is likely to meet with a far more indulgent audience than those which professional men have occasionally to face; but this is no reason why he should be careless as to his method of delivery, or of the matter delivered. Perhaps the er--worst fault er--which a lecturer can er--fall into--is the one indicated er--in this sentence. ‘To _err_ is human,’ in a wider sense, unfortunately, than Pope, the writer of that well-known line, ever dreamt of. Unless a would-be lecturer can conquer this tiresome habit, or any other trick of speech which he may have cultivated, by all means let him confine himself to the management of the lantern while some one else acts as showman.

If two people are thus managing an exhibition between them, and if the room be large, so that they are widely separated, some signal from the lecturer to indicate that he wants the next picture thrown on the screen becomes necessary. A bell, or anything that makes a noise, is distracting both to lecturer and audience. Still worse are verbal instructions from one to the other. I myself use an electric single-stroke bell with the gong removed, the hammer of which gives a little click unmistakable to the operator, but quite unheard by the audience. Such a bell can be placed close to the lantern, while its push is far away on the lecturer’s desk. Sometimes a string can be carried from lecturer to operator, a gentle pull of which will give the necessary signal. Some lecturers signal by uncovering a little pane of red glass in the back of their reading-lamp. But I think that any sight signal is inadmissible, because the operator has quite enough to do in attending to his duties without having his attention thus distracted. The signal, of whatever nature it be, should be given by the lecturer some seconds before he has finished with the picture in hand, otherwise there is an awkward pause while the operator makes the necessary change. Before the lecture begins, the reader should make himself not only thoroughly familiar with his subject, but should be also familiar with the different pictures which illustrate it. And this especially applies to the common case of those who have purchased or hired a set of slides and a published lantern reading--many of which are compiled by writers of repute, and are in every way excellent. Let him, then, carefully go through the reading beforehand, comparing each picture with the text, and making himself so familiar with its details that he is afterwards able, during performance, to point out anything to which attention may advantageously be directed. Particularly is this necessary in the case of an introductory map, where places of importance to the subject in hand must be pointed out. The most convenient form of pointer, by the way, is a Japanese fishing-rod, which telescopes into small compass when not in use.

For an evening’s lantern entertainment to be successful, a great deal depends upon the operator. With a mineral-oil lamp in a small room, his duties are not very onerous, for the lamp when once established should require no further attention, except it be to turn down a wick which shows symptoms of smoking. But he should be careful to have in reserve a glass or two to replace the front glass of the combustion-chamber, which may crack through some unexpected draught of air. His slides must all be numbered and in order. They may be each mounted in a wooden frame to fit the lantern stage, or else the lantern may be fitted with a permanent grooved slide in which the glass pictures are placed one after another, the last one pushing out the one before. Another plan, which is a good one to adopt where a single lantern only is being used, is to make use of what is called a panoramic slide. It is constructed like the one just described, only it is furnished with a travelling tape upon which each picture rests. The turn of a handle moves the tape, and the pictures travel forward panorama-fashion.

In the use of a double lantern furnished with lime-jets, there is plenty for two hands to do, for the operator has to keep his attention fixed not only upon the business of changing the pictures, but upon the condition of the lights. As the pressure of the oxygen gas varies as it is gradually consumed, so the supply of the two gases to the jets will want constant adjustment if the maximum quantity of light is expected. Extra weights, too, must be added as the pressure-boards gradually sink down. Beyond carefulness in this respect, the lantern operator must see to the occasional turning of his limes, taking care to do this when the lime wanting attention is not in actual use. He should also find time to wipe the glass of each picture with a leather before putting it in the lantern, for a film of moisture condenses on the surface, particularly in a room full of people.

The success of a lantern entertainment depends nearly as much on the competence of the assistant as it does on the powers of the lecturer. I am perhaps fastidious on this point, for my lecturing apprenticeship was served at the late Royal Polytechnic Institution, where operators were employed who had spent the best part of their lives in this particular work. It was seldom, indeed, that they made a mistake.

THE END.

BILLING AND SONS, PRINTERS, GUILDFORD.

Transcriber's Notes:

Italics are shown thus: _sloping_.

Variations in spelling and hyphenation are retained.

Perceived typographical errors have been changed.