764
��Popular Science Monthly
��An Improved Darkroom Lamp
A METHOD of darkroom illumina- tion is shown in the accompanying illustration. The negative may be examined thoroughly during the process of development without unduly exposing the plate. A two - candle - power in- candescent lamp is attached to a handle and enclosed by a hemispherical re- flector, closed at the front with a disk
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���A two candle-power ruby lamp allows close examination of ^negatives during the proc- ess of development
of dark ruby glass. The lamp is held near the plate and all the light is thrown downward so that the eyes receive only the light reflected from the plate.
Only a small section of the plate is exposed to the light at any time. When the lamp is not being used for this purpose, it may be laid face down on the table or suspended so as to light the darkroom. — George Yaste.
How to Send Coins by Mail
LAY the coin on a sheet of paper and describe a circle around it. Then with a knife, cut through the paper along the heavy lines, as indicated in the diagram. The coin may then be slipped underneath the central slip and the two flaps may be folded over the top.
��Cu^ on heavy fines
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��A piece of stiff paper cut as indicated will hold a coin securely for mailing
��A Locomotive Apron Lifter
THE device shown in the illustration is for holding up the apron between an engine and its tender, while coupling or uncoupling the tender. The apron is generally hinged to the cab brackets and is a mean thing to handle. This appliance is simply^a small clamp which slips in over the edge of the apron and has a small chain with a hook on the other end which is fastened on hooks around the cab handhold. The details are clearly shown in the diagram. Note the small set-screw, which is tightened after the device is put on the apron, to prevent accidents. — J. K. Long.
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���The "apron" between locomotive and
tender will be held up safely with this
device during coupling
Uncoupling Pipes
THE threads on steam, water, and gas-pipes are usually coated with white lead or paint when the pipes are coupled together; old pipes that have been put together in this manner are usually hard to uncouple. If the juncture is heated, the paint or lead will soften and the pipes can be taken apart very readily.
When two pipes rust together, pour a little oil on the exposed threads and allow the oil to soak in for a few minutes. Then heat to make the oil penetrate. The pipes may then be taken apart easily. — F. M. Defendorf.
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