670 FRAGMENT* O 



In 1866 a great step in the intensi'fication of induced 

 currents, and the consequent augmentation of the magneto- 

 electric light, was taken by Mr. Henry Wilde. It fell to 

 my lot to report upon them to the Royal Society, but 

 before doing so I took the trouble of going to Manchester 

 to witness Mr. Wilde's experiments. He operated in this 

 way: starting from a small machine like that worked in 

 your presence a moment ago, he employed its current to 

 excite an electro-magnet of a peculiar shape, between 

 whose poles rotated a Siemens armature;* from this arma- 

 ture currents were ootained vastly stronger than those 

 generated by the small magneto-electric machine. These 

 currents might have been immediately employed to produce 

 the electric light; but instead of this they were conducted 

 round a second electro-magnet of vast size, between whose 

 poles rotated a Siemens armature of corresponding 

 dimensions. Three armatures therefore were involved in 

 this series of operations: first the armature of the small 

 magneto-electric machine; secondly, the armature of the 

 first electro-magnet, which was of considerable size; and, 

 thirdly, the armature of the second electro- magnet, which 

 was of vast dimensions. With the currents drawn from 

 this third armature, Mr. Wilde obtained effects, both as 

 regards heat and light, enormously transcending those 

 previously known. f 



But the discovery which, above all others, brought the 

 practical question to the front is now to be considered. 

 On the 4th of February, 1867 X a paper was received by the 

 Royal Society from Dr. William Siemens bearing the title, 

 " On the Conversion of Dynamic into Electrical Force 

 without the use of Permanent Magnetism." J On the 14th 



*Page and Moigno had previously shown that the magneto-electric 

 current could produce powerful electro-magnets. 



fMr. Wilde's paper is published in the "Philosophical Trans- 

 actions " for 1867, p. 89. My opinion regarding Wilde's machine 

 was briefly expressed in a report to the Elder Brethren of the Trinity 

 House on May 17, 1866: " It gives me pleasure to state that the 

 machine is exceedingly effective, and that it far transcends in power 

 all other apparatus of the kind." 



\ A paper on the same subject, by Dr. Werner Siemens, was read 

 on January 17, 1867, before the Academy of Sciences in Berlin. In 

 a letter to Engineering, No. 622, p. 45, Mr. Robert Sabine states 

 that Professor Wheatstone's machines were constructed by Mr. Stroh 

 in the mouths of July and August, 1806. I do not doubt Mr. 



