INTRODUCTION. XIX 



colored shades over the screen occasionally, by using the 

 tinters, gives a sense of a brighter light. 



For large public exhibitions, the mixed jet lime-light is 

 necessary, and is in common use, mostly in two lanterns, 

 with the dissolving cock, for producing the dissolving 

 views. A single lantern with automatic cut-off and glass 

 slides produces an agreeable effect, and is much easier and 

 cheaper. See Manual, page 168. 



The Mixed Jet can also be used to great advantage in 

 educational institutions, where the gases are stored in gaso- 

 meters, as recommended in the Sciopticon Manual, page 182. 



This makes available, at a moment's notice, the best 

 light, and it can be used in the daytime, with such dark- 

 ening of the windows as can easily be effected by shutters 

 or curtains. 



The effects of the Concentric Jet, No. 2, is scarcely 

 inferior to the mixed jet, and there is a great advantage 

 in using it, wherever the house gas is within reach, because 

 it is easier to manage, and because it is not at all dangerous. 



The Alcohol Burner, No. l,is somewhat more difficult to 

 manage than either of the other forms of lime light, but 

 is used to advantage where hydrogen or house gas is not 

 easily obtainable. 



The Sciopticon with its oil lamp, rather than with its 

 lime light, though less effective, continues to be the choice 

 of the many, for its being always ready, easy to manage, 

 and inexpensive to use; showing with great brilliancy 

 and steadiness for hours without readjustments or annoy- 

 ance, and without heating the oil or cracking the glass ; 

 while to close an exhibition, we have no further care than to 

 turn down the wicks. 



As a Home Influence, it is worthy of all praise. Without 

 drudgery or delay it transforms the drawing room into an 

 art gallery, where the family circle may pass their leisure 



