purpose, under the supervision of Mr. George E. Henshaw, an expert amateur photographer of New York City.

A cam-like bit of wood, weighing four grains troy, is placed over the junction of the spring with the trigger, when set ready for an exposure in the air. The tripping of the trigger by a thread from the operator on the ground tips and upsets this cam, to which is pendant just below the camera a bright red celluloid sphere two inches in diameter. This ball, attached to a thread, drops a length of four feet, and is readily discerned at great altitudes and indicates that

an exposure has been made. The shutter

cannot be

snapped

without

the ball drop

ping; the ball cannot be dropped without the shutter having been snapped both open and shut.

Some of the views taken with this camera cover the width of the lower part of the business portion of New York City, and from Washington Square southward to Staten Island in the Harbor of New York.

The unique conditions under which aërial photographs are taken present special difficulties and new problems that can be overcome only by repeated trials. High up in the air the camera is completely immersed in an intensity of light that searches out its every cranny, and it will be often found that a box that has long been thought absolutely light-tight is surprisingly and disappointingly vulnerable. Foggy plates and those that reveal "ghosts" of a most weird and unaccountable character show that "absolutely light-tight" applies to ordinary conditions only.

trees and other objects will show as the eye is accustomed to see them. If in taking a picture directly downward the swing-back be adjusted at a large angle of divergence from the camera's line of vision, parts of the resulting picture will be out of focus.

The effect of

perspective,

so familiarly called to mind by the converging tracks of a railroad, is evident in the horizontal lines of an aërial picture and also in the apparent tendency, when the photograph is taken directly downward, of the walls of high buildings to come together at the bottom. There is really a double perspective somewhat confusing to the eye.

Distortions so familiar to everyone who has used a fixed camera can be minimized by directing the camera at an acute angle with the plane of the landscape, and, of course, the greater the altitude at which an exposure is made the farther away will be the foreground.

By using a camera with a swing-back adjusted so that the plate will be practically parallel with the vertical objects in the view, the landscape in the picture will appear horizontal, and church-spires, tall buildings,

VOL. XXII.-65

The smoky and dusty haze that overhangs our great cities is a pronounced hindrance in successful picture-taking, especially in the early part of the day when the sunlight is deflected as if passing edgewise through a plate of glass, and in the late afternoon the lights and shadows are unpleasantly emphasized. The growing interest in and popularity of kite-flying, and the wide attention which new experiments with kites as a lifting power attracts, show plainly that it will be a matter of only a short time when the camera will be a part of the equipment of every kite-fleet. Aërial photographs may become as common as the snap-shots that now confront us on all sides.

PHOTOGRAPHY has been for a number of years a most valuable help to astronomers in mapping the stars and making records of other celestial phenomena, and of late many interesting applications of the camera have been made in taking pictures of all sorts of luminous objects. Remarkable and realistic photographs of firework displays, foundry and rolling-mill interiors, blast furnaces, and other weirdly picturesque scenes have been accomplished, the best of them with the aid of the flash-light. The nonluminous details are taken with the flash, while fires and other brilliant lights make their own impressions.

Moonlight effects in photographs have long been admired by the uninitiated, and fully appreciated by both amateur and professional photographers for their beauty, and many plates, too, have been spoiled by snap-shotters who have accepted moonlight as the real illuminator of these views, and accordingly focused directly on this beautiful orb of night. Moonlights with the moon herself in evidence are really sun photographs, that is, pictures taken with a

rapid exposure, the camera pointed toward the sun generally in the late afternoon or early morning and with clouds between the lens and the direct rays.

Many charming so-called night-pictures are taken by making two exposures, a short one in the rapidly diminishing afternoon sunlight, to get an impression of buildings and other dark objects, and another longer one after dark to print in the gas and electric lights that line the long street or mark out the roads and winding pathways of a city park.

It is only within the past two or three years, however, that actual night-photographs have been attempted with any considerable degree of success. Mr. W. A. Fraser, of the New York Camera Club, especially noted for his beautiful lantern slides, following the lead of Mr. Paul Martin of London, has succeeded in taking a number of charming moonlight views by the moon's diffused light, not looking her in the face, with an exposure of ten minutes; and some remarkable park and street scenes on snowy and rainy nights show, with sur

prising distinctness and truth, very picturesque and interesting after-dark aspects of New York.

Great care must be taken to have the camera—one with a tripod is essentialsolidly planted, and a watch must be kept to prevent the lights of any passing vehicle or belated bicycler from entering the field of vision. Moving objects not carrying lights make no impression. Mr. Fraser uses a double non-halation plate, which he backs as a further precaution. Halation (halo plus ation) is the milky-way-like haze so often seen in plates that have been exposed with the camera pointed toward a window or other direct source of light, and is caused by light being reflected from the back of the plate itself. Halation bothered photographers for a long time and has been the occasion of much learned discussion regarding the mysterious action of light. To prevent it, specially prepared plates are used having a double coating of the sensitive emulsion--one slow, the other fast. Backing is covering the back of the plate with some opaque substance; asphaltum,

or sheets of brown carbon tissue paper are often used. Where there are only gas-lights in the view the exposure is from eight to ten minutes; with electric-lights-those only which are enclosed in opal shades can be successfully included from two and a half to three and a half minutes.

Mr. Alfred Stieglitz, another amateur and member of the Camera Club, whose notably artistic photographs have attracted attention and won many medals both in this country and in Europe, has also been experimenting for the past year with night-pictures. Realizing how much more interesting such scenes could be made by the introduction of a human element, Mr. Stieglitz has made a number of views with figures in them with an exposure of less than a minute. With regard to efforts to entirely eliminate halation, he uses non-halation plates, but without the backing, saying justly enough that a certain degree of halation naturally belongs to these night-pictures, especially when taken as he prefers to take themduring a storm. Everyone has observed the fuzzy globes of light that surround a

gas or electric-light on a rainy or a foggy night that add so much to the vagueness and mystery of the surrounding gloom.

These night pictures suggest all sorts of valuable and interesting possibilities. We may before long be able to photograph the crowds and scenes around the bulletin boards on election night, the frantic enthusiasm of a great out-door political meeting, and other great gatherings. By the use of the camera at night

many memorable scenes can be made a part of permanent history in all their details, that now can only be generalized by

These night-views are most effectively shown by means of lantern-slides, when the luminosity of the original scenes is brought out with surprisingly realistic effectiveness. They necessarily lose some of their quality in reproduction.

AM a professor in a small college. When I took my degree of Doctor of Philosophy, fifteen years ago, I had very definite ideas of what my future was to be. By dint of severe economy, and with the aid of scholarships, prizes, tutoring, and vacation earnings, I had managed to complete my undergraduate course with fair credit. I liked study, and had always been much with books; quite naturally, therefore, I determined to make teaching my profession. I realized, however, the need of further study if my teaching was to be very successful; and, accordingly, though after considerable hesitation, I decided to continue my work for three years and obtain, if possible, the coveted doctorate. The great difficulty in the way was lack of money. To overcome that, I borrowed fifteen hundred dollars, on practically unlimited time, and with this, supplemented by a fellowship which I was fortunate enough to hold for two years, I paid my university bills. In the meantime I married, under the delusion that I could not wait and that two could live almost as cheaply as one. My wife, like myself, was poor, but she was well educated, practical, and with faith in me beyond what I have ever felt I deserved. An opportunity to attend to some business matters for a friend, and at the same time to convoy a small party of boys, gave us a chance to spend a summer in Europe. This was devoted to travelling and sight-seeing, as I purposed returning to Germany before long for a more extended stay. At the end of the three years i obtained my degree, and about the same time had the satisfaction of seeing my name attached to a technical article in a magazine the first fruit of my anticipated career as a scholar. I was then twenty-five years old. I had been well trained, knew what sound scholarship meant, and was regarded by my instructors and friends as a man of promise. The next thing was to get a chance to teach. VOL. XXII.-66

I had several times heard painful accounts of the difficulties and trials of university graduates in their quest of employment, and how some of them, after drifting about for several years from one thing to another, had ended by "accepting" positions in preparatory schools. Fortune was kinder to me. In the course of a few weeks three opportunities presented themselves. The first was an instructorship in the university, with a salary of $1,000 a year and a reasonable chance of promotion. The proposition was attractive, and seemed quite in line with my scholarly ambitions; several of my friends in the faculty urged me to accept. After careful deliberation I declined, my real reason (not, however, the one publicly stated) being that the salary was too small to allow me to live in

in the style that I deemed essential. Not only must I live, but I must also pay my debt; and fifteen hundred dollars, with accumulating interest at seven per cent., began to seem a large sum. The next offer came from a scientific school in a distant city, where I could have an appointment for five years as assistant professor at a salary of $1,800 a year, and after that, if my work was satisfactory, a full professorship and $2,500 a year. This I also refused, mainly because a former instructor, in whose judgment I had great confidence, told me he feared that I would find the atmosphere of a scientific institution uncongenial, and my work, which was not in physical science, of secondary importance. By this time my state of mind was one alternately of lofty independence, in view of the flattering offers I had received and declined, and of anxious desire to get my immediate future settled. So when, a little later, I was asked, without solicitation, to allow my name to be presented as a candidate for a vacant professorship in an old and well-known college, I consented, with only so much apparent hesitation as would give the impression of deliberateness and careful consideration. I was elected without opposition, and in due time was formally installed.