MAGNETO-ELECTRIC MACHINES. 65 



*ed ring marked upon the glass.* The top AA is then to be 

 replaced, care being taken that the guides, c c c, are all external 

 to the glass ; that is, the plates only are to be in the acid : the 

 guides require a slight compression in thus returning them to 

 their place. The screw D of the regulator is to be turned until 

 the fine point within the glass tube is clear of the coloured water. 

 The conducting wires. The conducting wires are now well 

 secured, one in each binding screw E E : should the vibration 

 under the screw F not be regular and rapid, the screw must 

 be turned higher or lower as is necessary. The operator now 

 taking hold of the handles, and the screw of the regulator D 

 being slowly turned by the operator to meet the coloured water, 

 the current will pass, the strength increasing as the point 

 descends, et vice versa. 



SUSPENDING OPERATIONS. The top A A is to be steadily 

 raised to the position shewn by the dotted lines a a, when the 

 guides ccc will spring and suspend it until again required for 

 use. 



Considerable care being necessary in the construction of this 

 machine, we would caution purchasers, in order to avoid disap- 

 pointment, that in no case can a machine be warranted perfect, 

 unless it has the name and address of the sole manufacturers by 

 appointment, (Messrs. WILLATS, Cheapside, London), conspi- 

 cuously placed upon it, and having the signature of the inventor 

 upon the label. 



MAGNETO-ELECTRIC MACHINES. 



As Electricity, under certain conditions, gives rise to magnetism, 

 so magnetism, in its turn, can be made to evolve electricity. 

 Our celebrated countryman, Faraday, was the first to discover 

 that magnetism conjoined with motion may be made the source 

 of electricity. It would be foreign to a work of this kind, and 



* The acid employed is one part of sulphuric acid to eight parts of water. 

 This being once supplied, will last for months, any little loss by evaporation 

 being made up with water. 



