 | 1840 - 444 pages
...operation (or until the heat has acted equally upon all parts of the plate) it will be perceived that the surface of the silver has obtained a whitish tint or coating and then the action of the heat must cease. This effect may be obtained by other means ; for instance,... | |
 | William Newton, Charles Frederick Partington - 1840 - 442 pages
...minutes, (or until the heat has acted equally upon all parts of the plate,) it will be perceived that the surface of the silver has obtained a whitish tint or coating, and then the action of the heat must cease. This effect may be obtained by other means ; for instance... | |
 | 1841 - 444 pages
...operation (or until the heat has acted equally upon all parts of the plate) it will be perceived that the surface of the silver has obtained a whitish tint, or coating, and then the action of the heat must cease. This effect may be obtained by other means ; for instance,... | |
 | 1913 - 1150 pages
...minutes (or until the heat h;is acted equally upon all parts of the plate), it will be perceived that the surface of the silver has obtained a whitish tint or coating, and then the action of the heat must cease. wards and forwards on the furnace, so as to heat it equally... | |
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... uppermost. Under the plate is placed a lighted lamp, which is to be moved about, so that the flame shall act equally upon all parts. When the plate has been submitted to this operation for about five minutes, (or until the heat has acted equally upon... 