HISTORY OF SCIENCE. 



improvement of Pixii's apparatus was devised by Saxton, who made 

 the armature move while the magnet remained fixed. The apparatus 

 then assumed the form shown in Fig. 294, where A is a steel horse- 

 shoe magnet, and F F are the two armatures. At p is the contrivance 

 for gathering up the currents in one direction. The wheel E, on which 

 is fixed a handle for turning, is connected by an endless band with a 

 small pulley on a spindle, which passes between the two coils, and to 

 which they are attached by the cross-piece D. R R are brass handles 

 used when the machine is employed to administer shocks. 



FIG. 295. GRAMME MACHINE. 



Many ingenious forms of powerful magneto-electric machines have 

 been constructed in more recent times. Mr. Holmes in 1862 ex- 

 hibited such a machine driven by steam power, and applied the currents 

 it produced as a source of light. Mr. Holmes' machines were suc- 

 cessfully set in action at some of our lighthouses, as the source of the 

 electricity for the electric lamp. Every one who has of late years 

 crossed the narrow part of the English Channel at night must have 

 noticed the brilliant lights of the South Foreland, and the splendid 

 beam from Cape Grisnez on the French coast : all these lights, be it 

 remembered, are the immediate fruit of Faraday's discovery. Mr. H. 

 Wilde, of Manchester, invented a powerful form of magneto-electric 

 machine, in which the armatures are wound parallel to their axis of 



