I. ELECTRICAL MACHINES, ETC. 315 



1331. Model of a Magneto-Electric Machine, designed to 

 illustrate the advantage gained by the use of an electro-magnet in 

 place of the usual permanent magnet. William Raynoi\ 



This model of a magneto-electric machine is one that has been constructed 

 for the purpose of showing the great increase of the electric current by the 

 use of an electro-magnet in place of the permanent magnet, when such magnet 

 is excited or charged by a galvanic cell ; and this plan may be applied with 

 advantage to all magneto-electric machines using soft iron magnets. 



1331a. Sketch and Description of an Improvement in 

 Magneto-Electric Machinery. This improvement is ob- 

 tained by using two armatures on one spindle, to be fixed one on 

 each side of the magnet, and placing them at right angles to each 

 other, so that one is in full action when the other is changing its 

 polarity. William Raynor. 



1332a. Portable Magneto- Electric Machine, with double 

 coiled magnet. Harvey, Reynolds, and Co. 



1249a. Volta Faradaic Machine, with arrangement in the 

 pocket for taking shocks ; also giving interrupted or continuous 

 current, the batteries being of the constant Leclanche form. 



Harvey, Reynolds, and Co. 



1336. Dynamo-Electric Light Apparatus, making 480 

 revolutions per minute, with an expenditure of 6 horse-power gives 

 a light of from 12,000 to 1,5,000 normal candles. 



Siemens and Halske, Berlin. 



In these machines the inner iron core is fixed. Around this core revolves 

 a German silver bobbin, upon which is wound in a peculiar manner eight 

 double circuits of covered copper wire, these circuits terminating in the 

 metallic segments, which are successively brought as two opposite poles into 

 contact with the wire brushes. The magnetic field in which this bobbin 

 revolves (on its own axis) is formed by electro-magnets, the continuation of 

 the cores of which are curved iron bars, and these bars are so arranged as to 

 be brought as near as possible to the revolving bobbin. The current given 

 by these machines is continuous and in one direction. 



1336a. Dynamo-Electric Light Apparatus. This ma- 

 chine gives a light of 4,000 normal candles with 850 revolutions 

 of the armature per minute, with an expenditure of work equal to 

 3 horse-power. Siemens and Halske, Berlin. 



133Gb. Dynamo-Electric Light Machine producing a 

 light equal to 1,000-1,300 normal candles with about 1,100 revo- 

 lutions of the induction cylinder per minute and an expenditure of 

 1 to \\ H.P. The machine is 640 millimetres in length, 540 milli- 

 metres width, and 225 millimetres height. 



Siemens and Halske, Berlin. 



1336c. Magneto-Electric Machine to give a constant 

 current. The apparatus has 50 steel magnets, and the current 



