44: DESCRIPTION OF GALVANIC BATTERIES. 



ployment of an electro -magnet, formed by a current of electricity 

 produced from a magneto-electric machine, instead of that generated 

 in a voltaic battery ; and such an electro-magnet may be very advan- 

 tageously used for magnetizing large bars of steel, or for producing 

 very powerful magnets. Any of the known forms of magneto-electric 

 machines will serve thus to convert a bar of steel to an electro- 

 magnet, but the patentee prefers to use one composed of four, eight, 

 or any other number of permanent magnets, having double the 

 number of armatures, and coiled with strong wire of about 60 feet 

 in length. The machine about to be described has been found to 

 answer well in practice. In this machine the steel magnets are 

 composed of eight plates of a U form, weighing about 30 Ibs. each 

 plate, and there are eight such compound magnets, all the north 

 poles of which are arranged on one side of the machine, and the 

 south poles on the other side, although this precise arrangement is 

 not essential, and may be varied. The armatures are of soft iron, 

 weighing about 15 Ibs., and are coiled with about 60 feet of copper 

 wire, of No. 4 guage, and insulated in the usual manner. The arma- 

 tures revolve in a brass wheel, and are caused to pass as near to the 

 poles of the magnets as practicable, the commutator or break acting 

 on the whole eight magnets at the same instant, so that the current 

 of electricity shall always pass in one direction, and the surfaces of the 

 whole of the 64 plates be in combination at the same time. The bar 

 of soft icon used as the electro-magnet with this machine weighs 

 about 500 Ibs., and is coiled with bundles of about 30 copper wires 

 of No. 1 6 guage, and about 60 feet in length (the bundles are formed 

 by binding a series of uncovered wires together into one covered 

 strand or bundle), and the power of the -electro-magnet will depend 

 upon the power of the permanent magnets used in the machine, both 

 as to the weight it will support from a keeper, and as to its capabi- 

 lity of rendering bars of steel permanently magnetic by contact there- 

 with. It will, therefore, be evident that by having two sets of the 

 permanent magnets, and changing them in such machine, their sup- 

 porting power may be increased by continued charges or passes from 

 the electro-magnet thus produced. In one form of electro-magnetic 

 machine represented and described under the second head of the 

 invention, the steel bars or permanent magnets are eight in number 

 (these bars may be of cast or soft iron, but when soft iron is employed, 

 bars of steel permanently magnetized will have to be used in con- 

 junction with them), of a U form, and arranged around a circle with 

 their poles pointing towards the centre. Each arm of each of the 

 magnets has attached to it straight bars of steel, also rendered per- 

 manently magnetic (of which any desired number, and of any length 

 or size, may be employed, according to the strength of magnet re- 

 quired), which are so placed as to be out of the influence of the 



