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BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



Set of Spirals. (Fig. 336.) 

 This is an instrument of ex- 

 treme beauty. It consists of 

 five spirals, enclosed in glass 

 tubes, about 14 inches long, 

 connected by brass sockets 

 to a handsome polished maho- 

 gany stand ; on the top of 

 each spiral is a cap terminat- 

 ing in a brass ball ; in the 

 centre of the stand is a swell- 

 ed glass pillar with a cap, and 

 terminating in a pointed wire, 

 on which is mounted to turn 

 easily, a wire terminated by 

 balls, so that as it revolves it 

 shall come very near to each 

 of the spiral tubes in succes- 

 sion ; to the cap of the swelled 

 pillar there is a hook, to attach 

 a wire to the prime conductor ; 



if the movable flyer be started it will continue to re- 

 volve, communicating a spark to each of the spirals, 

 and they will be rapidly illuminated. 



Price, $10.00. 



Luminous Word. (Fig. 337, next page.) The luminous 

 word is formed by pasting strips of tin foil on a plate of 

 glass, having portions cut out as represented in the cut. 

 The side of the glass coated is protected from injury by 

 another glass plate, and both fixed in a frame, having a 

 handle, or mounted on a stand. A brass knob and wire 

 connect with the first piece of foil, and a hook and chain 

 with the last. On presenting the knob to the conductor, 

 the chain being connected with the ground, lines of fire re- 

 presenting the word, occasioned by sparks passing at the 

 same moment through all the spaces, will be seen. 



Price, $3.00. 



Luminous Crescent. (Fig. 338, next page.) This is the 

 same instrument in principle, and formed in the same man- 

 ner, having a frame about fourteen inches square representing 

 luminous lines in the form of a crescent. Price, $3.00. 



