Editorial Comment for this plate:

A FLASH-LIGHT INTERIOR.

OUR frontispiece this week is an excellent example of an ingenious method of photographing interiors by means of magnesium light.

The negative was made by Mr. E. M. Pine, of Philadelphia, inventor of the excellent magnesium lamp which bears his name. We are indebted to Messrs. Morris Earle & Company, photographic merchants, of Philadelphia, for the negative as well as for the description which follows:

“It was desired that a photograph be taken of a suite of rooms in Trymby Hunt & Co ‘s large show rooms, Market St., Philadelphia. There was no day-light to make the exposure by, and it occurred that a magnesium light would be desirable; but with the long series of rooms one flash would have been useless, hence it was concluded that a number of exposures in separate rooms would make the exposure for the entire plate satisfactory. The camera was placed in a room from which could be seen, through the doors of the various rooms, a mirror at the back end of the vista. Separate flashes were made of fifteen grains of pure magnesium powder in Pine’s flash-lamp, and two exposures from opposite sides of each room were made so that the shadows in every instance were softened and a satisfactorily timed exposure obtained, the lens being capped between the exposures, focusing having been done previous to the original exposure and registered on the bed of the camera for each distance of the separate rooms from the camera. After the first exposure the back of the camera was run back to focus No. 2, and so on until four exposures were made on one plate. The development came up satisfactorily, and made, as the print shows it, a well timed exposure throughout. This picture having been shown to an engraver, he remarked immediately on the sharpness of distance from foreground to background, and that such an exposure in halls and dwellings would be of great use in their work, enabling them to engrave without the difficulty of extra work of sharpening up the background previous to engraving. The exposure was made on a Cramer plate, sensitometer sixty, with a wide-angle Beck Autograph Lens, 6 ½ x 8 ½, f/16 stop, with cap exposure.” (p. 339)