ELECTRICAL APPARATUS. 



271 



by a glass tube covered 

 with sealing-wax, to serve 

 as an insulating handle, by 

 which the inner coating 

 may be lifted from the jar 

 when that is charged with- 

 out communicating a shock 

 to the operator. Arrange 

 the jar with its coatings, and 

 charge it, it will act in every 

 respect as an ordinary coated jar ; charge the jar, and 

 without discharging it, remove the inner coating by its insu- 

 lating handle. If this coating, when removed, be examined, 

 it will be found not at all, or but slightly electrified ; lift the 

 jar carefully from within its outer coating, and examine that 

 it also will evince no sign of electricity. Fit the jar up 

 with -the other pair of movable coatings, that have not been 

 electrified, and apply the discharging rod ; an explosion and 

 spark will ensue, proving that the coatings are only the con- 

 ducting materials from one side of the glass to the other, 

 and that it is the glass itself on which the fluid is accumu- 

 lated. The annexed cut shows the usual form of these jars. 

 Price, with one set of coatings, $2.00. 

 " two " " $3.00. 



Magic Pictures. (Fig. 294.) Fig. 294. 



This consists of a frame of maho- 

 gany, or other wood, about twelve 

 inches square, sometimes having a 

 handle on one side to hold by, 

 having in a groove a plate of glass 

 confined, about ten inches square, 

 the middle of which is coated .with 

 tin-foil on both sides of the glass 

 to within one or one and a half 

 inches of the edge, one side of 

 which is connected with the frame 

 and handle, and the other having 

 a picture pasted over the tin-foil. 

 To use, lay a piece of money on 

 the picture, and holding it by the 

 frame or handle, charge the picture by presenting a ball 

 from the conductor to the money. When charged, take 



