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 



m 



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 



■Fb/d/?ere 



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. 



■,2l' "-^^ ^^^ ^^ Cha/n 



¥¥M^ 



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. 



