414 MAGIC LANTERN AND MOVING PICTURES [Cn. XI 



ADJUSTMENT OF THE MAGIC LANTERN ATTACHMENT FOR USE IN 

 CONNECTION WITH THE MOVING PICTURE MACHINE 



579. The adjustment of the arc lamp and condenser for the 

 moving picture part is of much greater importance and is more 

 difficult than that for the magic lantern attachment, hence, no 

 attention should be paid to the projection of lantern slides until the 

 projection of moving pictures is perfect. 



In most outfits the lamp-house moves sidewise on some lateral 

 rods. When pulled towards the operator the lamp is in line with 

 the moving picture objective, and when pushed away from the 

 operator until it hits a stop, it is in line with the lantern objective. 



Push the lamp-house on these lateral rods until it is held by the 

 stops. A lantern slide is put in the holder and the lantern objec- 

 tive support is loosened and the lantern objective moved sidewise 

 until it is over the spot of light from the arc and moved back and 

 forth until the image of the slide is in focus on the screen. If there 

 are shadows on the screen not due to malposition of the carbons, 

 use an objective with larger lenses. 



If the lantern picture does not occupy the same place on the 

 screen as the moving picture it may be the fault of the side adjust- 

 ment of the slide-holder, or it may be due to faulty alignment of the 

 arc lamp and moving picture head. If this should be the case 

 move the lamp-house sidewise until the lantern-slide picture 

 occupies the proper position on the screen. Then move the arc 

 sidewise until the screen is well lighted and clamp it in position. 

 When, now, the lamp-house is pulled into position in front of the 

 moving picture objective the spot of light may not fall upon the 

 aperture plate but to one side. If it is not in the right position do 

 not alter the adjustment of the arc lamp but move the lamp-house 

 as a whole to one side until the spot exactly covers the aperture 

 plate. Then fasten the stop, so that the lamp-house will always 

 occupy the same position when pulled toward the operator. 



580. Management of the arc lamp. During an exhibition it 

 is necessary to watch the arc lamp to see that it is burning prop- 

 erly. There are several ways of burning the arc which will give a 

 good light : 



