THE ELECTROPHORUS. 



199 



We take a lacquered tea-tray about a foot long, and cut out a sheet of 

 thick wrapping paper, so that it wHl lie over all the level portion of the tray. 

 At ea :h side of this sheet of paper we fix two bands of paper, as in the 

 illustration (fig. 201), so as to serve as handles. The tea-tray should be 

 placed upon two tumblers to support it and to insulate it, glass being a " non- 

 conductor." (We will speak of conductors and non-conductors presently.) 

 We have now our Electrophorus made ready for action ; let us proceed to see 

 how it will act. 



First, rub the thick packing paper over a hot fire or a stove, and the 

 friction must be continued for some time, until the paper has become 



- Simple Electrophorus. 



thoroughly dry, and as hot as possible without charring. When this has 

 been accomplished, place it quickly upon a wooden table, and rub it rapidly 

 and energetically with a clothes' brush, dry and hard as can be obtained. 

 Place the paper upon the tray; touch the tray with the knuckle, and draw 

 away the paper by the handles fixed to it (see fig. 201); a spark will result. 

 Then if the paper be replaced upon the tray, and the hand again presented, 

 the same result will follow. This experiment may be repeated five or six 

 times, at least, with success. 



We have in this tea-tray and its paper covering a real electric machine. 

 How can we manage to provide a Leyden jar to contain our electricity? 

 Nothing is more easy. Let us take a tumbler and partly fill it with shot; 



