396 OPERATING ROOM [Cn. XI 



554. Position of the machine. The machine should be 

 located so that its optic axis is perpendicular to the screen or the 

 pictures will be distorted. If the machine cannot face the screen 

 directly it is better to have it in the middle of the room and pointing 

 upward or downward, or to have it at the same height as the screen 

 and pointing slightly to one side. The worst possible distortion 

 occurs when the machine is pointed obliquely downward as it must 

 be when placed in one side of a gallery. 



555. Tent or booth for temporary operation. For a single 

 performance the machine may be laid on a table in the middle of 

 the auditorium just as with a magic lantern or it may be enclosed 

 with a temporary booth or tent to enclose any stray light and to 

 overcome the distracting effect of the machinery. 



556. Permanent operating room. Permanent installation 

 should include an operating room large enough so that the machine 

 or machines can be operated without hinderance or loss of time 

 from lack of sufficient space. This is very essential in any place 

 where even a short delay is so disagreeable to the audience. The 

 operating room should be easy to get to and it should be well 

 ventilated. It should have a large flue at least 50 cm. (20 in.) in 

 diameter, connecting with the outside of the building. All open- 

 ings in the operating room should be provided with shutters which 

 will close automatically in case of fire. The room should be pro- 

 vided with incandescent lamps and extension cords to use while 

 working around the machine and finally there should be an electric 

 fan and a chair for the operator. Every machine should be 

 accessible from all sides. Film boxes should be placed where they 

 can be easily reached. Sufficient tools for ordinary operation, a 

 supply of carbons, pins, film cement, and extra condenser lenses 

 should also be handy. A shop-room equipped for making repairs 

 to the machines and for doing jobs of wiring should be near the 

 operating room. It is not advisable to try to do such work in the 

 operating room itself. 



The operating room is to be at all times kept like a battle-ship in 

 time of war, with the decks cleared for action, nothing there which 

 is not actually required. 



