INTRODUCTION. Xxi'll 



Nature or Art? 



An unreasonable prejudice prevails, to some extent, 

 against all slides not photographed from nature. When 

 there is a choice, as, for example, between a photograph of 

 the Egyptian Pyramids and an artist's representation, as 

 roughly shown,, page 113 of the Manual, the sun picture 

 surely has the advantage ; yet something can be said, even 

 in this case, for the artist, who gathers the details of many 

 chance observations into one view, and groups the camels 

 and Arabs into an artistic pose more picturesque than 

 would come within the range of a photographer's average 

 luck. Historic and art pictures, and scientific illustrations, 

 which have been wrought out by the best skill and learn- 

 ing of the present and the past, can, for the most part, only 

 be copied into slides from these works of art. 



Strong or Faint? 



It is a mistake to suppose that pictures intended for the 

 Sciopticon should be selected with special reference to the 

 light used. The proper density for the Sciopticon flame 

 illumination differs little, if any, from what is best for the 

 lime light proportionally enlarged. Dense pictures fogged 

 in the high lights, may be shown a little, by lime light, and 

 the glaring defects of coarse pictures may show less by oil 

 light, but neither class is worthy of being recommended. 

 The class of customers most anxious to secure clear, bright 

 pictures, are professional exhibitors with a lime light. 



The Bad and the Good. 



It is matter for regret, that with our present facilities for 

 producing good slides of every class, so many bad ones 



