390 TRANSACTIONS OF THE 



I am aware that these points cannot well be understood without an 

 explanatory diagram, but I will endeavor to explain how a model might be 

 constructed which would illustrate these three points. 



Let us suppose that three groups of four magnets each will be sufl&cient 

 for illustration. Cotton reels will very aptly represent magnets with the 

 wire coil. By a series of disks arranged at suitable distances from each 

 other, the force is continued from one to another so as to produce a stroke 

 of adequate length. Thus by continuing the power through a sufficient . 

 number of magnets, the force is obtained for useful purposes. 



It has been considered too costly, but when the power is fully attained 

 it will be far cheaper than steam. Prof. Liebig goes out of his way (Ag- 

 ricultural Chemistry) to run a tilt against electro-motive power. He says 

 it is altogether fallacious ; that zinc is represented by an equivalent of 

 carbon (coal), so that, according to the experiments of Despretz, six pounds 

 of zinc, in combining with oxygen, develop no more heat than 07ie poicnd 

 of coal, he maintains that the heating power of the current is the equiva- 

 lent 01 the mechanical power through electro-magnetism, or in other words, 

 that the heat developed by the passage of the current, ought to raise 

 steam enough to furnish a power equivalent to the electro-magnetic power 

 of the same current, and from the fact that the mechanical force derived 

 from the steam raised by the heating power of the current is so small, com- 

 pared with that obtained by the combustion of coal, he arrives at the con- 

 clusion that electro-magnetic power "can never be used." 



Those who choose to think for themselves are not turned aside from in- 

 vestigations by the discouragements thrown in the path, but heedless of 

 the dried leaves of theory of those who, without the comparative anatomy 

 of thought, beg the question, seek to apply the dynamic effects of magnetism 

 to machinery. 



A powerful magnet resembles a steam engine with an enormous piston, 

 with an exceedingly short stroke. Hitherto every application of electro- 

 magnetism that has been put to a practical trial, has been at variance with 

 the laws of electricity or of mechanics ; and also, that the power of elec- 

 tricity, when applied in the form of an electro-magnet, is wonderfully great 

 from small means. The difficulties will in due time yield to knowledge. 

 What a grand problem will be solved when electro-motive power shall 

 everywhere supplant all other motive powers, — a motive power without 

 fire, and applicable everywhere it is wanted. 



The triumphs of science should be ever regarded as the manifestations 

 from a higher Providence, developing new powers for men, and preparing 

 the instrumentalities by which it is brought about. 



Mr. Hearder said that Mr. Hjorth, of Copenhagen, had lately constructed 

 an electro-magnet of large size, with an attractive force of some hundred 

 pounds at a distance of upwards of three inches. 



Iron is only susceptible of a certain amount of magnetism. 



Mr. Henley said he had expended hundreds of pounds of his own, and 

 several thousands of other people's, without success. He had made a mag- 



