SCIOPTICON MANUAL. 195 



the Sciopticon by a tube and flange, so that it can readily 

 be removed. 



The object carrier is made of strong plate glass, pressed 

 down by an adjustable spring, admitting of a delicate move- 

 ment of over one inch perpendicular and two inches lateral. 

 Two sliding bars, fitted to the edges of the glass plate, hold 

 the objects, which may be of different sizes, to the stage. In 

 principle it is what is known by microscopists as Zent- 

 mayer's glass stage. If a secondary condenser is required, 

 it is fitted to the attaching tube back of the stage. 



THE MEGASCOPE. 



Although the light reflected from the illuminated opaque 

 object in the opaque lantern is dim, as compared with the 

 direct rays through a magic lantern slide, and, notwith- 

 standing the dispersion of a large portion of even this 

 reflected light from the line of the Megascope objective, 

 yet the image of small objects may be thrown upon the 

 screen on a large scale with sufficient distinctness, not only 

 to be interesting, but to be practically useful for purposes 

 of illustration. 



Bright objects presented at the proper angle, such as a 

 watch with its movements, flowers, minerals, beetles, butter- 

 flies, etc., show quite brilliantly, while the images of duller 

 objects, or of plain pictures, are hardly suggestive of the 

 title of Wonder Camera, commonly applied to this arrange- 

 ment. 



Only a portion of most objects can be in focus at once, 

 for the lack of a flat surface. To bring out a distinct image 

 of even a flat object or picture, requires, theoretically, a 

 larger and better objective than ordinary lantern projec- 

 tions, as may be seen in Fig. 14, page 25, where each 

 point in the transparent object transmits (on the supposi- 

 tion that the light proceeds from a point) a single ray in the 



