282 



Popular Science Monthly 



A Homemade Focusing Hood for 

 a Hand Camera 



THE plate camera, although a little 

 slower to arrange for procuring a pic- 

 ture, will usually give better results than 

 other kinds, 

 owing to the 

 fact that it can 

 be brought into 

 perfect focus, 

 by adjusting 



A hcx)d for the camera back for keeping 

 light from ground glass while focusing 



the image shown on the ground glass. 



The greatest difficulty in doing this has 

 been in cutting off the side lights. This 

 is usually done with a cloth thrown over 

 the head, which method is uncomfortable 

 and slow. 



The hood, shown in the illustration, can 

 be attached very easily and can be tele- 

 scoped small enough to carry conveniently 

 in the pocket or case. First, cut four 

 pieces of paste-board about 2 in. in width 

 and long enough to fit around the frame 

 of the camera. Two of these pieces should 

 be slightly shorter than the others. Sew 

 the four pieces together to form the frame. 

 In pulling the joints together, at least 

 1/16 in. should be left to allow the frame 

 to fold when placed in the pocket. A 

 piece of black oilcloth is then procured 

 and cut according to the pattern shown. 

 White oilcloth may also be used just as 

 successfully. 



After stitching the V-shaped edges to- 

 gether, the shape is pyramidal. Now 

 place the larger opening over the paste- 

 board frame, allowing it to lap about 

 1 in., and sewing it firmly to the frame. 

 Fasten a wire around the opposite or 

 smaller opening, and hem the oilcloth 

 over the wire. 



When this hood is placed over the cam- 

 era, the door of camera can be opened 

 back into it, allowing a perfect view for 

 focusing. — Chas. Claude Wagner. 



An Indestructible Paper Weight 

 and Blotter 



A BLOTTER and paper weight which 

 is practically indestructible, can 

 easily be made by mixing 7 parts (by 

 weight) of gypsum, one part of potato 

 flour and a small portion of water. Just 

 enough water should be used to dampen 

 the mixture. The ingredients should im- 

 mediately be poured into a well greased 

 mold, and there allowed to dry thor- 

 oughly. Then they will be quite ready 

 for use. — W. S. Standiford. 



Making Bone Black from Scraps 

 of Leather 



THE apparatus illustrated is for the 

 purpose of manufacturing bone 

 black — animal charcoal or ivory black, as 

 it is called. I have made this pigment for 

 black shoe polish or paste, discoloring 

 liquids, filtering, etc. 



It consists of an ordinary piece of pipe 

 — the size depending on the amount to be 

 heated, or burned — capped on one end, 

 with the other end left open to make it 

 convenient for filling and to provide 

 escape for the gases. The pipe is half 

 filled with scraps from old shoes and har- 

 ness. The filled pipe is then laid with 

 the capped end in a furnace or in the fire- 

 box of a stove, allowing the open end to 

 extend out where the gases coming from 



.Pipe cap 



Leathei' scraps 



Gases burn as 

 •they come out 



Arrangement of a pipe for burning leather 

 scraps to make an ivory black pigment 



the pipe will burn during the operation. 

 The animal charcoal obtained from the 

 leather scraps is free enough from any 

 mineral substance to need no acid treat- 

 ment whatever. — Henry Klaus. 



