17 



Solar camera as used 

 to facilitate the pro- 

 duction of illustrations 

 from negatives and from 

 iransp a r e n t 

 objects. 



Fig. 2. 1, steel girder to left of window affording part of the support to 

 the^ ordinary camera 3 ; 2, cross-piece supporting camera 3 ; 4, support for camera 

 lucida, same being here represented as attached to an ordinary lens carrier; 5, 

 vertically adjustible horizontal platform; 6, drawing board; 7, horizontal ways 

 lor 6; 8, object in position to be drawn natural size; 9, mirror of ordinary camera 

 lucida; 10, 11, camera lucida support; 12, light-tight roller-blind used, when 

 unrolled as a diai)hragm for the cone of light from the projector: 13, solar-pro- 

 jector set in special window casing near floor; 14, the negative being projected 

 at 23; 15, 15, uprights carrying the adjustable sheet of glass on which the draw- 

 ing 23 is being produced from the negative 14; 16, wooden frame for sheet of 

 glass 18; 17, metal braces by which the frame 16 may be clamped at the required 

 angle; 18, sheet of glass through which as well as through the paper 22, 

 the image is viewed; 19, roller blinds to shut off extra light; 20, 21, 

 sticks to which the drawing paper is attached with drawing tacks, these sticks 

 being^ easily adjustable under the sand-paper-lined wooden springs-bars 24; 22, 

 drawing paper; 23, image being drawn; 24, wooden bar lined with sandpaper and 

 hinged at 25 and constantly pulled inward by a spiral snring at 26, so as to lightly 

 but firmly grip the sticks 20, 21; 27, screw legs on which afterthe apparatus has 

 been adjusted it can be raised so as to remain firm during the subsequent opera- 

 tions of focussing and drawing; 28, one of the four castors on which the whole 

 apparatus is adjustable back and forward on the floor to vary the magnication. 



