I. ELECTRICAL MACHINES, ETC. 313 



terrupted, so that the spark appears at the point of interruption. Faraday, 

 who was the first to observe the induction currents, obtained the spark by 

 using an electro-magnet ; the arrangements, however, of Nobili and Antinori 

 were the first that constituted a true magneto-electrical machine. And we 

 may also remark that, at the same time, Nobili and Antinori obtained the 

 electric spark, likewise, by means of the natural magnet of the museum, an 

 enormous parallelepiped of about 50 x 65 x 78 centimeters in dimension. 



1114. Saxton's Magneto-Electric Machine. Copy of the 

 original machine made by Mr. Saxton, and exhibited by him 

 before the third meeting of the British Association, held at Cam- 

 bridge in the year 18337 John O. N. Butter. 



This machine was made specially for the contributor by Mr. Saxton, 

 immediately after the meeting at Cambridge, and has been in his possession 

 ever since. It is capable of producing sparks, shocks (through the tongue), 

 and decomposes water. It also reproduces the ordinary phenomena of electro- 

 magnetism. 



The machine is described in Daniell's " Introduction to Chemical Philosophy," 

 1843, p. 585, sec. 873. 



1316. Ladd's Dynamo-Magneto-Electric Machine. 



William Ladd $ Co. 



Invented March 1867. (See Proceedings of the Royal Society, No. 91, 

 1867.) 



This was the first machine with two armatures, one being employed to excite 

 the electro- magnets and the other to produce an electric current, which may 

 be used for any purpose to which a battery is applicable. 



1316a. Ladd's Dynamo-Magneto-Electric Machine, 



with two wires on one armature. This machine will heat 15 

 inches of platinum wire. William Ladd $ Co. 



1317. The first Magneto-Electric Machine, with circular 

 magnets, 1866. William Ladd fy Co. 



1318. Magneto-Electric Machine, with circular magnets, 

 larger form, 1867. William Ladd $ Co. 



1319. Magneto-Electric Machine (direct current). 



James How fy Co. 



1320. Magneto-Electric Machine (Duchenne's form). 



James How fy Co. 



1321. Magneto-Electric Machine (Clark's form). An early 

 machine by Logemann^ of Haarlem. James How fy Co. 



1322. Electro-Magnetic Coil Machine, for medical ap- 

 plication. Primary and secondary currents. James Hoiv fy Co. 



1323. Magneto-Electric Machine, with alternate current 

 for production of light. La Societe V Alliance. 



A magneto-electric machine, with four discs or 64 bobbins with alternate 

 current for the production of light. This machine requires a driving power 

 of 3 H.P. when revolving from 400-450 times per minute. 



