THE PARTS OF A LANTERN 15 



be so. But besides the want of appearance, there is the ob- 

 jection to a simple metal body that it becomes very hot, and 

 may manifest this fact very suddenly and unpleasantly when 

 any manipulation is necessary. For this reason all the better 

 lantern bodies are made of wood, lined with an iron or tin 

 casing supported at a small distance from the wood, so as to 

 keep the outer body cool. 



The shape of a single lantern body may vary a great deal, 

 and has some connection with the radiant employed. With 

 Argand lamps (either gas or oil), which require a tall glass 

 chimney, a body is still employed (almost of necessity) rather 

 tall in proportion; and the earlier lime-light lanterns were 

 similarly made, from custom. But the introduction of tho 

 Sciopticon form of lamp caused a revolution in the form of 

 body also. There being no wick chimney, the tall chimney of 

 the flame chamber was attached to the lamp itself, and the 

 body of the lantern was lowered. All lanterns of the edge- 

 wick class are now made with low bodies ; and the same are 

 found ample for the lime-light. 



The wood of the body should be perfectly plain and sound 

 in grain, old and well-seasoned. Any ' ornamentation * is out 

 of place, as will be remarked upon again. 



Where exhibitions may have to be made in various places, 

 it is of some importance to have a door on both sides of the 

 lantern. Most people work from the right side (as the lantern 

 faces the screen), but this is not always possible, especially 

 with experiments. In all lanterns used with the lime-light, 

 each door should be furnished with a sight-hole glazed with 

 dark blue glass, through which the state of the lime can be 

 examined without dazzling the eye. For a lantern used only 

 with paraffin oil, sight-holes are useless, the flame being 

 examined through a sight-hole at the back of the lamp. 



The back of the body also demands a word. For Argands, 

 it is closed in entirely. For paraffin lamps it needs little con- 

 sideration, the lamp itself being closed in, with the exception 



