12 

 The New Cut-off. 



Hitherto the advantages of the Automatic Cut-off (see 

 Manual, p. 167) have been confined to the Gas Sciopticon, 

 and to the use of glass slides only. In the modified form, 

 the flap or curtain next the objective is closed at pleasure 

 by a latch under the fingers of the left hand, and is opened 

 by the outcoming slide. 



A brass spring, shaped like an archer's bow, faces the 

 wooden base of the stage and holds the framed slide, or 

 slide carrier, when glass slides are used, by bearing at the 

 sides of the picture-opening. The glass slide carrier is held 

 down, and firmly in place, by the first cut in the stage spring. 



Crystal slides are in place in this carrier when flush with 

 the condenser ; French slides are pushed along till the finger 

 comes to the junction of the condenser ring and the bottom 

 groove ; English square slides must be pushed in till the 

 forefinger hits the wire spring that holds them. 



The best way to stop a framed slide exactly in the right 

 place, without interposing any obstacle to its outgoing, is 

 to take it an inch from the end, with the thumb nail in a 

 cut which is, or should be, marked in each, and push it 

 horizontally along the stage till the thumb strikes the con- 

 denser ring. 



The operator (stationed behind the instrument, be it al- 

 ways remembered) may pass the slides through from right 

 to left, panorama style, without using the cut-off, if he 

 chooses. It is sometimes necessary to leave the curtain 

 closed till the tinters are drawn up, as for effect slides, etc., 

 which can be done by not crowding the outcomiug slide 

 forward. 



