ELECTKIC L1GHT1XO. 120 



Mr. Starr then set to work to devise a suitable dynamo-elec- 

 tric machine, and, following his usual course of starting from 

 first principles, concluded that all the armatures hitherto con- 

 structed were defective in one fundamental element of their 

 arrangement. The thick copper- wire surrounding the soft iron 

 core necessarily follows a spiral course, like that of a coarse 

 screw-thread ; bit the electric current or lines of force, which 

 it is designed to pick up and carry, circulate at right angles to 

 the axis of the core, and extend to some distance beyond its 

 surface. The problem thus presented is to wind around the 

 soft iron a conductor that shall be broad enough to grasp a 

 large proportion of this outspread force, and yet shall follow its 

 course as nearly as possible by standing out at right angles to 

 the axis of the armature. This he endeavored to effect by 

 using a core of square section, and winding round it a broad 

 ribbon of sheet copper, insulated on both sides by cementing 

 on its surfaces a layer of silk ribbon. This armature was laid 

 with one edge against one side of the core, and carried on thus 

 to the angle ; then turned over so that its opposite edge 

 should be presented to the next side of the core ; this side to 

 be followed in like manner, the ribbon similarly turned again 

 at the next corner, and so on till the core became fully inclosed 

 or armed with the continuous ribbon, which thus encircled the 

 core with its edges outward, and nearly at right angles to the 

 axis, in spite of its width, which might be increased to any 

 extent found by experiment to be desirable. 



At this stage my direct co-operation and confidential com- 

 munication with Mr. Starr ceased, as I remained in London 

 while he went to Birmingham in order to get his machinery 

 constructed, and to apply it at the works 'of Messrs. Elkington, 

 who had then recently introduced the principle of dynamo- 

 electric motive-power for electro-plating, etc., and were, I 

 believe, using Woolrich's apparatus, the patent for which was 

 dated August 1st, 1842, and enrolled February 1st, 1843. 



I am unable to state the results of his efforts in Birmingham. 

 I only heard the murmurs of the capitalists, who loudly com- 

 plained of expenditure without results. They had dreamed the 

 same dream that Mr. Edison has recently re-dreamed, and has 

 told the world so loudly. They supposed that the mechani- 

 cally excited current might be carried along great lengths of 

 wire, and the carbons interposed wherever required, and that 

 the same electricity would flow on and do the duty of illumina- 

 tion over and over again as a river may fall over a succession 



