Electro-Magnetism, as a Moving Powef\ 107 



tJie feioer the magnets and the smaller their size, {luith certain 

 limits,) the greater the ratio of tnechanical poioer obtained. ySuch 

 experience as this appears discouraging, but is by no means suffi- 

 cient to prove the experiment infeasible. The numerous faiku'es 

 are such as have been incident to the prosecution of all inventions 

 in their early stages. It is much to be regretted, that in our coun- 

 try the invention should be a subject of mercenary speculation, 

 when in reality it has no value except as an experiment, and that 

 the public have been so far misled, as to withdraw that counte- 

 nance and encouragement which the experiment really merits. 

 We can not but deplore, that such an interesting branch of science 

 should be so traduced, and that the very name of electro-magnet- 

 ism should be coupled with empiricism. 



There can be no doubt in the mind of any one who may have 

 seen an electro-magnetic engine, that it furnishes a mechanical 

 power already applicable and useful to a certain extent, provided 

 the maintenance of that power be not expensive and difficult. 

 The application of this power cannot be expensive, if the mechan- 

 ical or working poiver of any number of magnets m a machine 

 increase in the direct ratio of the aggregate attractive force ; that 

 this rule does not hold in any of the plans of which, hitherto, we 

 have had any description, I shall prove, when the cause comes to 

 be considered. Yet in certain arrangements this law must ob- 

 tain, and although the necessary construction be at present some- 

 what complicated, yet ultimately it doubtless will be simplified. 

 At present, we have no means of computing the extent of mag- 

 netization which may be effected by a galvanic pair of given 

 surface, say a single inch, freshly immersed. It must very far 

 exceed that which we ordinarily recognize in our experiments. 

 By great care, I have succeeded in producing an attractive force 

 of over 800 pounds, by a galvanic pair having only ten square 

 inches of zinc exposed ; whereas with the usual arrangements, it 

 required two -or three square feet to produce the same power. 

 This power, t-hough so great for the means used, yet probably 

 was not near the maximum procurable from the same zinc sur- 

 face. It Avould seem, then, that if the above mentioned ratio ex- 

 ists in attainable forms of machines, the application of the power 

 cannot be otherwise than cheap. The difficulty of maintaining 

 a uniform power is by no means insurmountable. The faults 

 hitherto have been, the wearing and alloying of the pole-changer 



