45, COKNHILL, E.G., AND 122, REGENT STREET, W., LONDON. 



447 



FIG. 2687. 



FIG. 2702. 



FIG. 2686. 



FIG. 27.11. 



Each. 

 s. d. 



2697 



2698 



2698 

 2699 



2700 

 2701 

 2702 



2703 

 2704 



2705 



Each. 

 s. d. 

 18 



Double Wheel, of the Stellar form .... 

 Apparatus, exhibiting a Coil of Copper Wire rotating 



between the poles of a magnet (fig. 2698) ... 16 



Glass Tube, surrounded by a Coil of Copper Wire for 



magnetizing steel needles by induction ... 026 



Electrepeter or Commutator, for reversing the direction 



of Galvanic or Electro-Magnetic currents ... 1 10 



Dr. G. Bird's Inversor for ditto (fig. 2700) ... 110 



Bachoffner's Electrepeter, for ditto (fig 2701) . 160 



Apparatus for showing the opposite rotation of hooped permanent magnets 



and a straight electro-induced magnet (fig. 2702) . . . .200 

 Powerful Electro or Induced Magnet, having double wires, and movable 



coils for Dia-Magnetic experiments (fig. 2703) . . . 12 12 



Compound Electro-Magnetic Apparatus, consisting of a horse-shoe magnet, 



on brass foot, with levelling screws and sliding pillar, two rotating 



armatures, rotating coil, Ampere's bucket, mobile wire frame, helical coil, 



rotating cylinder, and two flood cups 3 10 



Callan's Primary and Secondary Coils on Stand . . . . 1 16 



FIG. 2682. 



FIG. 2079. 



FIG. 2711. 



