[Ill.u.s.tration: FIG. 66.--PHOTOGRAPH OF FROST. BY JAS. LEADBEATER.]

The most difficult question of all remains, the cause of the various forms of the hexagonal crystals, which frequently change in the same snowfall. Instead of advancing a new hypothesis, says h.e.l.lmann, it is better to acknowledge that we know nothing positively in regard to this. In our knowledge of the form and structure of the snow we have made great advance since the time of Kepler, but after nearly four hundred years, we cannot give a satisfactory answer to his question, "_Cur autem s.e.xangula? Why six-sided?_"

We do not know the special conditions which determine the formation of one or the other form of snow crystals. We have found that a low temperature favors the formation of tabular crystals; a higher temperature the star shaped crystals; these groups show such multifarious forms that it is necessary to seek for other causes which influence the formation of snow figures. There is offered here a broad field for new investigation and study.

We give a reproduction (Fig. 64) of a photograph of a curious group of crystals. Some water had been left in a 108 dish on a winter day, and a film of ice was seen floating on the surface. The formation of the crystals and the floral design were so beautiful that it was taken out and photographed. The delicate lace-like edging of the glacial tracery is the result of the deposition of h.o.a.r frost while draining off the water from the ice leaves and flowers and fixing the image in the camera.

Quite recently Mr. Jas. Leadbeater has favored us with some account of his beautiful work in this fascinating branch of photography, some samples of which are here given. He first makes his windows perfectly clear and waits for a keen frost. The camera is inside the room and a dark cloth-covered board is placed on the outside, leaning against a low balcony of wood. The exposure varies with the thickness of the crystals, from two to ten seconds, princ.i.p.ally with a very small stop.

Two reproductions of his pictures will be found on pp. 76-77.

PHOTOGRAPHING INK CRYSTALS.

The study of crystallization is undoubtedly an interesting and fascinating one, and photography may be made to play an important part in securing permanent records of these curious formations. If a drop of water containing a salt be allowed to drop upon a gla.s.s plate, it will, upon evaporation, deposite crystals of various kinds. In a recent article in _La Nature_, by Dr. E. Trouessart, a description is given of the beautiful crystallic forms deposited by a drop of ink on evaporation. The article is translated in the _Literary Digest_, from which we make extracts:

"Take a sheet of gla.s.s, deposit on it a drop of ink and spread the drop a little, uniformly; let it dry for a few minutes; then examine with a microscope, magnifying from 50 to 200 diameters, and you will be able to see the flowers of ink in process of formation under your eyes; that is to say, regular white crystal particles which detach themselves from the black or violet medium, and arrange themselves so as to form regular figures.

"If you are pressed for time, this beautiful result will easily be obtained by pa.s.sing the sheet of gla.s.s over a spirit lamp or a candle to evaporate the moisture. The crystals will then be smaller and more numerous, presenting the appearance of a dark firmament densely sprinkled with bright silvery stars. But if you have patience to wait for evaporation without heat, you will obtain larger crystals of more varied forms, arranging themselves as crosses, flowers, etc.

"These crystals may be varied indefinitely by modifying the compositions of evaporation, adding more ink, etc. But it is quite possible that different inks will give different results. The inks I use, like all the other inks in use, have a basis of sulphate of iron and gallic acid.

[Ill.u.s.tration: From "The Literary Digest." FIG. 67.--INK-CRYSTALS, AS SEEN THROUGH A MICROSCOPE.]

"By allowing the evaporation to proceed slowly, it is quite easy to watch the formation of the crystals. The geometrical figures are more or less perfect cubes, pyramids, lozenges, crosses, needles, etc., the pyramids being formed by cubes superposed one on the other, as in the pyramids of Egypt. The _flowers_ in our ill.u.s.tration are formed by the union of crystals, each of which represents the petals or sepals of a flower. The Maltese cross--the crucifer or four-leafed flower--is the normal regular form, but multiples of four frequently occur, by the formation of new crystals in the intervals; and also by the accidents of crystallization, we get flowers of three and five petals, resembling _Rubiaceae_, lilies, orchids, violets, etc."

PINHOLE PHOTOGRAPHY.

Although a lens is the most important part of the photographer's apparatus, it is not absolutely necessary for the production of photographs. Very good pictures can be made by means of a pinhole.

Remove the lens from the camera, and insert in its place a sheet of thin, hard cardboard. In the centre make a tiny hole with a fine-pointed needle made red-hot. Another method is to make a large hole in the cardboard, and paste over it a piece of tinfoil and make the pinhole in this. The essential point is that the hole be perfectly round without any burring at the edges. The most perfect arrangement can be obtained by getting a watchmaker to drill a fine hole through a piece of sheet metal. The diameter of the hole should not be greater than one-fiftieth of an inch. Whatever is used, cardboard or metal, it should be blackened all over to prevent the reflection of light in the camera. The focusing gla.s.s should be brought within about 6 inches of the hole. Owing to the small amount of light admitted, focusing is very difficult. It can be done by pointing the camera towards the sun and focusing its image. For the same reason the exposure is very long, ranging from ten minutes to half an hour; it is, in fact, difficult to overexpose.

[Ill.u.s.tration: Negative by F. C. Lambert. From Anthony's International Annual, 1894. FIG. 68.--PINHOLE PHOTOGRAPHY.]

[Ill.u.s.tration: (Photograph made through a slit without a lens.) By Roland Briant. FIG. 69.--THE WHITE ROBE OF NATURE.]

It is usually stated that no focusing is required, the larger the plate the wider the angle, but according to Prof. Pickering, 12 inches is the maximum distance for sharp work.

Peculiar diffused effects can be obtained by using a fine slit in place of the pinhole. The picture shown on page 82 is an example.

FREAK PICTURES BY SUCCESSIVE EXPOSURES.

We have already described the various remarkable photographic pictures which may be taken by successive exposures with the same individual in different positions against a perfectly black and non-actinic background. This, however, is not easily obtained, and a French photographer, M. Bracq, has invented an ingenious attachment to a camera by which the same effects may be obtained with any background and under the ordinary conditions of amateur photography. The following description is from _La Nature_ translated in the _Popular Science News_.

[Ill.u.s.tration: FIG. 70.]

The apparatus, Fig. 70, is attached to the back of the camera, and consists of a frame suitable for holding the usual ground gla.s.s, or plate holder. Directly in front of the plate holder is placed an opaque screen perforated with a horizontal slit the width of the photographic plate used. By means of a screw and a crank the screen with its opening may be made to move up and down before the plate, thus allowing all parts of it to be successively exposed. A pointer connected with the screen shows the position of the slit at any time when it is covered by the plate holder.

The operation of the apparatus is evident from the above description.

To take the picture ill.u.s.trated in Fig. 71, for instance, the table with the boy upon it is placed in the proper position and supported by planks, another table, or in any convenient way. After properly focusing it on the ground gla.s.s, the screen is screwed down till the opening is at the bottom of the camera, and the plate holder being placed in position, the slide is drawn and the handle turned till the indicator shows that the opening has reached a point corresponding to the image of the bottom of the table on the plate. The slide is then replaced in the plate holder, the table and its support removed, and the boy placed in the second position, and the exposure continued by s.c.r.e.w.i.n.g up the screen until the entire plate has been impressed with the double image, which, upon development, appears as shown in the ill.u.s.tration.

[Ill.u.s.tration: FIG. 71.]

The perforated screen may also be made to move horizontally as well as vertically across the plate, and by a combination of the two directions the same individual may be taken four or more times in different positions in the same photograph. Many amusing and astonishing effects may be obtained by the simple means which will readily suggest themselves to any practical photographer.

WIDE-ANGLE STUDIES.

[Ill.u.s.tration: Copyright, 1894, by W. J. Demorest. FIG. 72.--A PHOTOGRAPHIC FEAT.]

By the use, or rather the abuse, of a lens having a very wide angle, say, 100 degrees, some very amusing effects can be obtained by apparent exaggeration of perspective. We say apparent advisedly, for if a view made with one of these lenses, say of 5 inches focus, be viewed by the observer at a distance of 5 inches from the eye, the perspective will appear correct; but, of course, this is never done under ordinary circ.u.mstances. Every person, unless extremely short-sighted, will hold a photograph at a distance from the eye of about 12 or 14 inches.

[Ill.u.s.tration: FIG. 73.--A WIDE-ANGLE STUDY.]

The effect of using a wide-angle lens under ordinary conditions is to make objects in the foreground appear ridiculously large, while those in the background have a diminished appearance. Fig. 72 is an example of this; it is hardly necessary to observe that the gentleman's pedal extremities were not so gigantic as represented in the photograph.

Fig. 73 is another and scarcely less painful example of this exaggeration.

In the _Practical Photographer_, some time ago, it was humorously suggested that sportsmen could, by means of the camera, bring home apparently indisputable evidence as to their skill or prowess. Thus, for instance, you and your friend Jones have been out fishing together, and realized the truth of the old saying about anglers--_i.e._, "a worm at one end of a rod and a fool at the other."

You have, however, managed to catch a fish (any sort will do) about the dimensions of a good-sized sprat. It is the usual custom of anglers, I believe, to view their captures through magnifying-gla.s.ses before discoursing upon them. A better plan, however, is to photograph your fish, and then there can be no dispute whatever, because it is the popular belief that photography cannot lie. However, all that is necessary is to hang the fish in front of the camera to the bough of a tree, we will say, with a piece of black thread. You then retire several paces behind it, holding up your arm as if you were holding up the fish. Your friend will then adjust the camera so that the fish just comes under your hand, focuses, places a very small stop on, so as to get everything sharply defined, and makes the necessary exposure. Thus it is possible, with a little trouble, to obtain everlasting records of your marvelous day's sport, for you can easily make yourself appear to be holding a fish of gigantic proportions--say, 5 ft. long, or so. Fig. 74, 75.

[Ill.u.s.tration: FIG. 74.]

[Ill.u.s.tration: FIG. 75.]

Our ill.u.s.trations are from "Photographic Pastimes" by Herman Schauss.

With a very wide-angle lens it is also possible to make a photograph of a little suburban garden, and it will appear to resemble a park or palace grounds. This is a trick often adopted by auctioneers and estate agents, so that in viewing photographs of property, it is really impossible to form any safe idea regarding the place itself.

CONICAL PORTRAITS.

Amusing caricatures may be obtained by deforming the sensitive surface of the negative. The accompanying conical portrait is one.[6]

[6] From "Les Recreations Photographiques."