PRACTICAL PHOTO-MICKOGKAPHY. 



135 



is little sensitive as albumen paper, or our radiant little actinic 

 as an oil lamp, then in practice we require an optical system 

 known as a condenser. 



As we propose to treat of two methods only of enlarging we 

 shall touch but lightly on the subject of condensers. Our 

 purpose is to confine ourselves to the use of such sensitive 

 materials as gelatine-bromide emulsion, in which case we use 

 daylight reflected or diffused, and transmitted in parallel 

 pencils through the original ; or failing daylight, artificial light 

 concentrated and transmitted in converging pencils through 

 the original to a certain point at or near the optical centre of 

 the projecting system. 



ENLARGING BY DAYLIGHT. 



FIG. 32. 



The cut (Fig. 32) shows almost at a glance an arrangement 

 which if carried out in a reasonably workmanlike manner, will 

 fulfil every desideratum for enlargement by ordinary diffused 

 daylight. C is a camera capable of holding in its dark slide 

 the negative from which we propose to make an enlarged print 

 on paper or glass. C is fixed in any convenient manner to the 

 sides of an aperture, A, in a wall or shutter preferably facing 

 the north. F is a reflector of white blotting paper or any mat 

 white surface, not a mirror nor any shiny surface ; E is an 

 easel sliding easily along the base-board D ; E must keep at all 

 times parallel to the negative in the camera, and to start with 



