iv 



IXTBODUCTION. 



For plans and directions for building Gasometers for 

 Educational Institutions, say in the basement, that the 

 Lime Light maybe always available, at a moment's notice, 

 in the lecture room, without its being in the way or tedious 

 to prepare, see Manual, p. 182. As the apparatus 

 described is believed to be the best for its purpose yet 

 devised, and a style likely to be extensively introduced, the 

 plans and specifications are made as distinct as possible, 

 and easy for the builder to follow. 



PECULIAR ADVANTAGES 



OF THE 



OIL-U&ST SC10CTICOS. 



As the Sciopticon was originally known as an oil-light 

 lantern, its peculiar advantages as such may be first enu- 

 merated. 



1. The Flame-chamber, which is a distinctive 

 characteristic of the Oil-light Sciopticon, is in itself a small 



