Scientific American Supplement, No. 315, January 14, 1882 eBook

This eBook from the Gutenberg Project consists of approximately 129 pages of information about Scientific American Supplement, No. 315, January 14, 1882.

Scientific American Supplement, No. 315, January 14, 1882 eBook

This eBook from the Gutenberg Project consists of approximately 129 pages of information about Scientific American Supplement, No. 315, January 14, 1882.

One of the most extensive establishments for the purpose is that of Messrs. Winter, in Vienna.  They say to photographers in general:  If you will send us a portrait, either negative or positive, we will produce you an enlargement on canvas worked up in monochrome.  The success of their undertaking lies in the circumstance that they do not produce colored work—­or, at any rate, it is exceptional on their part to do so—­but devote their efforts to the production of an artistic portrait in brown or sepia.  In this way they can make full use of the dark brown photograph itself; there is less necessity for tampering with the enlarged image, and natural blemishes in the model itself maybe softened and modified, without interfering much with the true lines of face and features.  The monotone enlargements of Messrs. Winter, again, exquisitely as most of them are finished, do not appear to provoke the opposition of the painter; they do not cross his path, and hence he is more willing to do them justice.  Many a would-be purchaser has been frightened out of his intention to buy an enlargement by the scornful utterance of an artist friend about “painted photographs,” and in these days of cheap club portraits there is certainly much risk of good work falling into disrepute.  But a well-finished portrait in monotone disarms the painter, and he is willing to concede that the picture has merit.

“We cannot use English canvas, or ‘shirting,’ as you call it,” said one of our hosts; “it seems to contain so much fatty matter.”  The German material, on the other hand, would appear to be fit for photography as soon as it had been thoroughly worked in hot water and rinsed.  Here, in this apartment, paved with red brick, we see several pieces of canvas drying.  It is a large room, very clean, here and there a washing trough, and in one corner two or three large horizontal baths.  The appearance is that of a wash-house, except that all the assistants are men, and not washerwomen; there is plenty of water everywhere, and the floor is well drained to allow of its running off.  We are to be favored with a sight of the whole process, and this is the first operation.

Into one of the horizontal baths, measuring about 5 by 4 feet, is put the salting solution.  It is a bath that can be rocked, or inclined in any direction, for its center rests upon a ball-and-socket joint.  It is of papier mache, the inside covered with white enamel.  Formerly, only bromine salts were employed, but now the following formula is adopted: 

Bromide of potassium................... 3 parts. 
Iodide of potassium.................... 1 part. 
Bromide of cadmium..................... 1  "
Water................................ 240 parts.

Four assistants are required in the operation, and the same number when it comes to sensitizing and developing, all of which processes are commenced in the same way.  The bath is tilted so that the liquid collects at one end, and near this end two assistants hold across the bath a stout glass rod; then the canvas is dipped into the liquid, and drawn out by two other assistants over the glass rod.  In this way the canvas is thoroughly saturated, and, at the same time, drained of superfluous liquid.

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Scientific American Supplement, No. 315, January 14, 1882 from Project Gutenberg. Public domain.