Instantaneous Photography.

THE recent progress in the art of photography toward a greater sensitiveness in the plates exposed in the camera, has been so rapid, and attended with such generally happy results that it may be regarded as a real artistic and commercial gain. From a personal examination of the new emulsion process, as carried on in the studio of a leading photographer in this city, it appears that the taking of pictures is practically instantaneous. The new process and the extreme sensitiveness of the plates have really more of general interest than would first appear. To save time for the sitter posed before the camera is very well, but the discoveries that have sprung from pictures of people, animals, machinery, or other objects in rapid motion, are of far greater value, both as a matter of science and art. The studio had a glass roof of the usual shape and aspect, and the camera was of the common form, except that it was made with unusual care to exclude every trace of light from the sensitive plate, when placed in position for work. The box for carrying the plate was also made absolutely light-proof. The subject, a child of about two years of age, having taken the required pose, at the right instant the shutter of the camera (designed for quick movement) was opened and closed in apparently about one second, or perhaps less. The plate was then taken, in the tight box, to a dark room, where the daylight was completely excluded, and only a dim gas-lamp, shaded by ruby glass, was permitted. The plate appeared to be white, or about the color of ground glass laid on a white paper, and was perfectly dry, no trace of the picture being visible. It was then laid, sensitive side up, in a flat porcelain dish, and the developing liquid was “flowed" gently over it by tilting the dish up and down. The picture began to show the white lights almost imme. diately, and in five minutes was completely developed. The negative was then washed in clean water and plunged in the fixing bath, and after this was completed was very carefully dried in free air. The process, it will be seen, is quite simple, and as far as can be learned, is fairly uniform in its results. The plates, when taken from the camera, may be developed, fixed, and dried at once, or may remain in the dark for several hours, and be finished afterward, at the convenience of the operator. On one occasion, in this studio, eighty-two negatives were taken in less than ten hours, and all were left to be developed at night, and, in completing them, it was found that only in two instances were the sitters required to come again. The preparation of these highly sensitive dry plates has now become a regular business, and they may be obtained ready for immediate use. As they keep their actinic properties indefinitely, it will be seen that the whole art of photography is made much more simple, and the artist is enabled to take outdoor pictures or dark interiors with ease in situations where it would be impos

sible to use the older methods. There appear to be several formulas for making the dry plates, all much alike, and giving about the same result, the dif ference being chiefly in the degree of actinic sensitiveness. These have received the general name of gelatine-bromide processes, and the chief points of one of the formulas may be given as showing the main ideas underlying them all. The measures and figures given are taken from a late English work on the subject, and may be regarded as expressing the quantities required for making a small number of plates. The glass is first cleaned, and then coated with a film designed as a base, or substratum, for the sensitive emulsion, this film being made by putting the white of one egg in twenty ounces of water, and, in order to preserve the solution, adding one ounce of methylated spirit, and twenty drops of carbolic acid, the mixture being carefully flowed over the glass and dried. To make the emulsion, thirty grains of gelatine is put in two ounces of water in a glass beaker. To this is added fifty grains of pure bromide of ammonium, stirred in with a glass rod. At the same time, one hundred and fifty grains of gelatine is placed in three ounces of water in a second glass. Time is allowed for the swelling of the gelatine in the beakers, and then seventy-five grains of nitrate of silver is dissolved in one and a quarter ounces of water in a third glass. In a fourth glass ten grains of pure carbonate of ammonium is dissolved in one-quarter of an ounce of water. The beakers containing the gelatine and bromide and the silver nitrate are placed in hot water, and, at the same time, a white stoneware bottle is warmed by rinsing in hot water. When the gelatine and bromide have dissolved in the gentle heat they are poured into the warm stone bottle, and the heated silver nitrate is added, a little at a time, and well shaken. This mixing of the silver nitrate with the bromide salt must be conducted in an actinicly dark room, the sole illumination being from the ruby light. The carbonate of ammonium is then poured in and the bottle again shaken. This mixture forms the emulsion, and it is boiled by placing the stone bottle in boiling water for ten minutes, when it is removed and placed in cold water till reduced to about ninety degrees Fahrenheit. The contents of the fourth glass are then poured into the bottle and the whole is thoroughly shaken together. This preparation is the most highly sensitive material ever used in photography, and when properly spread on the glass makes the so-called dry plates with which instantaneous pictures are taken. For developing the negatives two preparations are used, one composed of one hundred and sixty grains of ammonium bromide, four ounces liquor ammonia, and four ounces of water; the second containing forty-eight grains of pyrogallic acid in two ounces of alcohol. These are properly mixed before using. A preparation may also be used for intensifying the neg

ative. This description of the process is not intended to give more than a general idea of the chemical basis of the emulsion process. The practical photographer has the formulas in every detail in recent publications, and others can buy the plates ready made. The process is still so new that some difficulties appear to be found in certain portions of the work, but these seem to spring from the very novelty of the materials and their preparation. Aside from the art interest in the new plates is quite another, that springs from the fact that it is now possible to take pictures of men, animals, and machinery in rapid motion, thus enabling us to view them in a way that would be impossible with the unaided eye. The first experiments in this direction were applied to the movements of a horse moving at full speed. The pictures, taken in series, showed that he performed muscular actions that were not before comprehended or even imagined. These pictures at the time attracted great attention, and instantaneous pictures have been since taken of dancers in a ball-room, of vessels and steam-boats in rapid motion, of all kinds of animals in motion, and of machinery in operation. As the pictures represent the movements at one instant of time, they give, as it were, a fixed view of a motion, precisely as if it were suddenly arrested in full action. In the case of animals, the motions of the nostrils are represented in the most singular manner, and the spokes of a steam-boat's paddle-wheel are shown apparently perfectly still while the spray and waves appear in active motion, or, rather, as they would look if they could be instantly frozen. It is clear the new process and pictures will open a wide and instructive field in art and in the study of mechanical action.

Disposal of City Refuse.

ATTEMPTS have been made from time to time to find some means of disposing of the waste of cities by burning it in some form of furnace; but for some reason best known to our city governments all these furnaces have been declared useless or unsuccessful. More recently a new style of cremating furnace has been made the subject of exhaustive experiment in disposing of the waste of a large city, and, from the reports made upon its operation, it would appear to work without inconvenience to the neighborhood, and at a material saving of expense. Two forms of furnaces have been erected, one called a "Destructor," for burning ordinary city rubbish, and a retort called a "Carbonizer," for burning streetsweepings to a cinder, or ash, suitable for fertilizing purposes. The destructor consists of a group, or battery, of furnaces, built of fire-brick, and tied together with iron rods. Each furnace has a sloping grate placed over a deep ash-pit, and covered with a reverberatory fire-brick arch. Behind the flue is an inclined flue, or arched passage-way, down which the refuse slides on its way to the fire. The battery of furnaces is covered with a platform, upon which the

carts bringing the rubbish may be driven from an inclined road-way connecting with the street below. Openings are provided in this platform over each flue to enable the loads to be shot directly into the furnaces. Iron doors are provided for these openings to prevent the escape of the products of combustion while the rubbish is being burned. At the back of the furnaces is a horizontal flue leading to the chimney, and connecting with each furnace by an opening at the top of the inclined flue. To prevent the material from falling into the flue, a bridge wall is placed at the top of the flue, and all the heat and smoke pass through and over the rubbish as it slides down toward the fire. It is found that in such furnaces all kinds of refuse are completely destroyed, the products of the combustion drawn from the ash-pit being clinkers, partly melted metals, and a fine ash. The metals are easily separated from the ash, and may be sold, while the clinkers are. ground and mixed with lime, to make a good commercial mortar. The waste heat of the furnaces is used to generate steam, and the power thus obtained is employed to grind and mix the clinkers. Each furnace is said to be capable of consuming seven tons of rubbish in twenty-four hours, and after the fires are once started they require no fuel, as the rubbish contains enough waste coal to consume itself, leaving only the expense of labor and attendance.

The carbonizer, for disposing of street-sweepings, is essentially an upright retort. The material is not brought into direct contact with the fire, but passes through a hot well, and is subjected to destructive distillation. The apparatus consists of an upright flue of brick-work, having inside a smaller flue, carried spirally around the inside. The lower part of this small flue, next the furnace that is placed at one side of the main flue, is made of fire-brick, while the upper part is formed of iron plates. At the top of the structure, the small flue connects with a vertical flue, leading to the ground and thence to the chimney. The fires having been started, the street-sweepings, condemned meat, and vegetables, are shot into the top of the furnace from a platform above, and fill the entire flue, and are charred or carbonized by contact with the hot plates and brickwork, and are discharged below in the form of an excellent fertilizer.

These two forms of furnaces are designed to be placed in a group, one chimney serving for both, the ash of the destructor being used as fuel in the carbonizer. They have already been adopted by a number of cities, and are reported to work at a material saving of expense, and with no inconvenience to people living near them.

"New Apartment-Houses."

IN the article under the above title in this Department for April, it may appear that Messrs. Pugin & Walter were designers of all the accompanying plans. The duplex flats were designed by Hubert, Pirsson & Co., of New York.

rally; him, too, I take in, just as I would a coyote, or a king, or a toad-stool, or a ham-sandwich, or anything or anybody else in the world. Where are you going?

You want to see Paris, to eat truffles, to have a good time; in Vienna, London, Florence, Monaco, to have a good time; you want to see Venice. Come with me. I will give you a good time; I will give you all the Venice you want, and most of the Paris.

I, Walt, I call to you! I am all on deck! Come and loafe with me! Let me tote you around by your elbow and show you things.

You listen to my ophicleide!

Home !

Home I celebrate. I elevate my fog-whistle, inspir'd by the thought of home.

Come in!-take a front seat; the jostle of the crowd not minding; there is room enough for all of you. This is my exhibition-it is the greatest show on earth-there is no charge for admission. All you have to pay me is to take in my romanza.

2.

1. The brown-stone house; the father coming home worried from a bad day's business; the wife meets him in the marble-pav'd vestibule; she throws her arms about him; she presses him close to her; she looks him full in the face with affectionate eyes; the frown from his brow disappearing.

5. The room in the third-class boarding-house; the mean little hard-coal fire, the slovenly Irish servant-girl making it, the ashes on the hearth, the faded furniture, the private provender hid away in the closet, the dreary back-yard out the window; the young girl at the glass, with her mouth full of hair-pins, doing up her hair to go down-stairs and flirt with the young fellows in the parlor. 6. The kitchen of the old farm-house; the young convict just return'd from prison-it was his first offense, and the judges were lenient to him. He is taking his first meal out of prison; he has been receiv'd back, kiss'd, encourag'd to start again; his lungs, his nostrils expand with the big breaths of free air; with shame, with wonderment, with a trembling joy, his heart too expanding.

for the fine ironing to-morrow-it is Third-day night, and the plain things are already iron'd, now in cupboards, in drawers stowed away. The wife waiting for the husband-he is at the tavern, jovial, carousing; she alone in the kitchen sprinkling clothes-the little red wood clock with peaked top, with pendulum wagging behind a pane of gayly painted glass, strikes twelve. The sound of the husband's voice on the still night air-he is singing: We wont go home till morning! -the wife arising, toward the wood-shed hastily going, stealthily entering, the voice all the time coming nearer, inebriate, chantant.

The wood-shed; the club behind the door of the wood-shed; the wife annexing the club; the husband approaching, always inebriate, chantant. The husband passing the door of the wood-shed; the club over his head, now with his head in contact; the sudden cessation of the song; the temperance pledge signed the next morning; the benediction of peace over the domestic foyer temporarily resting.

3.

I sing the soothing influences of home.
You, young man, thoughtlessly wandering, with
courier, with guide-book wandering.
You hearken to the melody of my steam-calliope.
Yawp!