PRINTING METHODS LANTERN SLIDES 99 



have used almost exclusively since its intro- 

 duction, a number of years ago. A shining 

 surface is detestable in a landscape print and 

 numerous other subjects, but it is perfectly 

 adapted to the delineation of a microscopic 

 object, when it possesses the peculiar proper- 

 ties which have made Velox altogether the 

 best printing medium for this class of work 

 that I have ever seen. The most delicate 

 details are rendered with the fidelity of a 

 glass transparency; they are not sunk into 

 the paper, but borne entirely upon its surface. 

 The printing may be done by lamp- or gas- 

 light, with even greater regularity and cer- 

 tainty than by day. The development is sim- 

 ple and sure ; there is no toning to be done. 

 Pure whites, glossy blacks, lovely half-tones, 

 are always obtainable, and the prints are 

 almost without doubt permanent, whilst the 

 paper itself keeps indefinitely previous to be- 

 ing printed upon. All of the operations may 

 be pursued in subdued daylight or by ordi- 

 nary lamp-light. No dark-room is necessary. 

 The paper itself is so heavy as really to re- 

 quire no mounting. Of more than 4,000 

 prints made three years ago for a portion of 

 the High schools of New York city, not one 

 was mounted on cardboard, yet they have 



