OF ELECTKO-GALVANIC APPAEATUS. 



a 



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183 



FIG. 2138. 



PIG. 2136. 



2134. MEDICAL COIL, improved, with sulphate of mercury battery, very portable, in 



form of a book . . . . . . 400 



2135. PEIMARY COIL, with handles for giving shocks, and very useful for increasing 



the intensity of galvanic batteries . . . . 18 6 



2136. Rhunikorff's Induction Coil, small size, with vacuum tubes and illustrated 



description complete, for showing a number of very beautiful and instructive 

 experiments (fig. 2136) ..... 5 5 



2137. COMMUTATORS of various sizes, for reversing the action of the galvanic current 



(fig. 2137), 10s. and upwards. 



2138. UNIVERSAL DISCHARGERS (fig. 2138), 8s. 6d. to . . 150 



IMPROVED RHUMKORFF'S COILS OR INDUCTORIUMS. 



2139. INDUCTORIUMS, each from . . . 5 to 10 



2140. to give 2|-inch. spark in air . . . 12 10 



2141. 4 . . . 15 10 



2142. 6 . . . 21 

 Inductormms of larger size made to order, the spark being strictly proportioned to the 



length of wire employed. 



2143. Magnetic Electric Exploder, in mahogany case with 2 keys . 16 10 



2144. 6 . 17 10 



2145. INDUCTION COIL, especially arranged for blasting purposes, in strong oak case 



9 15 



2146. Insulated Wire, for connections, per 100 yards . . 18 6 



2147. APPARATUS FOR EXPLODING GUNPOWDER. Improved magnetic exploder 



600 



