WILLIAM SIEMENS, F.R.S. 403 



i;o feet high. The mechanical effect thus realised amounts 

 to 3| HP., deduction being made for frictional losses of every 

 kind, and the experiment is interesting as showing a practical 

 application of electric energy to useful purposes. Considering 

 that t In- weight of the machine is only 3| cwt., and of the pump 

 about the same (the total being at any rate within half a ton), and 

 that the power could be easily augmented to 5 or 6 HP., I think 

 we may look forward to the time when our fire engines will be 

 worked on this principle. 



The Electric Storage Company have been kind enough to send 

 me some of their batteries, and I shall turn their current upon 

 this machine in order to produce the same results as shown before. 

 In this instance the effect, originally produced by the steam- 

 engine, has given motion to a dynamo-machine, the electricity 

 from which has been transferred to the secondary battery, where 

 it has produced chemical action such as I shall presently describe. 

 The store of chemical effect thus produced within the battery is 

 now made available in forming a current, which, passing through 

 the dynamo-machine connected with the pump, imparts motion to 

 the latter. I will now connect the current with a second dynamo- 

 machine to work a saw bench, giving motion at the same time to 

 another dynamo-machine, wound with comparatively thick wire 

 in order to set up a current of very low electrical potential. The 

 potential of the dynamo-machine outside the building is equal to 

 100 volts, but it is inconvenient sometimes to use a current of 

 such high tension, and my object in transferring the power derived 

 from a machine of high potential to another dynamo-machine 

 wound with thick wire is to obtain a current of low potential, 

 which in this instance does not exceed 10 volts. Such a current 

 could not harm a child, but is most effective where quantity 

 rather than high potential is required, as for instance, for electro- 

 lytic purposes. This is what may be called a tertiary machine, 

 and you will observe that it has more effect than either the 

 primary or secondary in heating an iron wire of considerable 

 thickness (^th of an inch thick), it being what is called a quan- 

 titative current. We will now connect the current with a little 

 toy railway, and you will see the result. I may call this a 

 quaternary transmission of force. The steam-engine transferred 

 its energy to a dynamo-machine ; this dynamo-machine gave motion 



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