The American annual of photography . in the sketches (Figures i and 2). Twopieces of 16 gauge brass, A, ij^ in. in diameter are drilledwith six concentric and equidistant holes j4 in. in diameter, ^ ^ o« 0« 0 C-i= -it—* 0 IW 1 0 ^7 L>~ fStu c/ on tvAic)a- Holt-y for iffooJ cs -scr - 2. iTftj - / rcf mreU. 19. Figure 2. carefully countersunk and with another hole in the center onwhich the discs are to revolve. Some brass or copper as thinas possible, 1/200 in. thick is preferable, is obtained and astrip is cut two or three inches long and about a quarter of aninch in width. Through this thin
The American annual of photography . in the sketches (Figures i and 2). Twopieces of 16 gauge brass, A, ij^ in. in diameter are drilledwith six concentric and equidistant holes j4 in. in diameter, ^ ^ o« 0« 0 C-i= -it—* 0 IW 1 0 ^7 L>~ fStu c/ on tvAic)a- Holt-y for iffooJ cs -scr - 2. iTftj - / rcf mreU. 19. Figure 2. carefully countersunk and with another hole in the center onwhich the discs are to revolve. Some brass or copper as thinas possible, 1/200 in. thick is preferable, is obtained and astrip is cut two or three inches long and about a quarter of aninch in width. Through this thin metal are carefully made thefive holes, which are to be one millimeter, () ; three-quartersof a millimeter, () ; one-half millimeter, () ; three-eighths of a millimeter, () ; and one-quarter of a milli-meter, () in diameter. The best way to get these sizes accurate, and this is neces-sary, is to beg, or borrow, a micrometer inthe metric system and then take friend wifes needle book and 136. «>CO Q•4 CO mo HUO oo H measure up the different sizes until tive needles are foundwhich correspond to the sizes given. I found the five I wantedin a very short time. The holes in the thin metal are made bylaying the strip of metal on a blotter, which in turn is laid ona discarded negative or similar piece of glass. The largest needle (No. i) is then pushed through as far asit will go, withdrawn, and the metal turned over and laid onthe glass. A small burr or protrusion will be noticed, and thismust be removed by lightly rubbing with a piece of very fineemery paper glued to a light stick. The metal is then turnedface up again and the needle pushed a little farther throughand the burr again removed. This process is repeated untilthe needle will pass through its entire length, except the eyepart, which is usually somewhat larger than the body of theneedle. Care must be taken that the needle is at all times atright angles to the metal being perfo
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1919
