422 



NEGBETTI AND ZAMBEA, HOLBOKN TIADUCT, B.C., 



FIG. 2455. 



FIG. 2457. 



FIG. 2461. 



2454 



2455 



2456 

 2457 



Hand Spiral, consisting of two glass tubes with brass caps, the inside one 

 covered in a spiral form with spangles of tin foil, showing when presented 

 to an excited conductor, a spiral stream of electrical light (fig. 2454) 



3s., 4s., 5s. 6d 



Set of Five Spirals, Best, with coloured tubes (fig. 2455), on mahogany 

 pedestal, with insulated revolving balls in the centre, which, by their 

 motion, produce a splendid succession of spiral lines of light 220 



Luminous Chain Experiment, (fig. 2456) 15 



Revolving Spiral, on stand. The electric fly or whirl revolves by the dis- 

 persion of electricity from the points, presenting a very beautiful appearance 

 in a dark room (fig. 2457) 16 6 



FIG. 2468. 



FIG. 2464. 



FIG. 2465. 



