163 Prof. Page on Electro-Magnetism as a Moving Power. 



great rapidity and an equable motion. In all the engines 

 hitherto used^ there is a loss of power at the instant of the 

 change of current, owing to the production of a secondaiy cur- 

 rent moving in the opposite direction, and to this loss is owing 

 the fact that these engines cannot be rendered available. Prof. 

 Page had in view the obviating of this difficulty when he com- 

 menced his recent investigations, and has full success in his new 

 invention. 



The Secretary of the Navy on Tuesday sent to the Senate, in 

 answer to their call for information, the following report from Pro- 

 fessor Charles G. Page, being an outline only of his experiments in 

 the application of electro -magnetism : — 



Washington, August 30, 1850. 



Sir, — In compliance with your request, I have the honour to report 

 to you the progress made in my experiments, under the act of March 

 3rd, 1849, appropriating ^20,000 for " testing the capacity and use- 

 fulness of the electro-magnetic power as a mechanical agent for the 

 purposes of locomotion and navigation, and the probable cost of using 

 the same." 



A schedule of expenditures incurred up to this date, amounting 

 to ^12,667"28, is herewith annexed, by which it will appear that 

 considerably more than one-third of the appropriation remains yet 

 unexpended. Outstanding bills remain amounting to about ^1000, 

 most of which is charged at the Navy Yard for material, which, when 

 deducted, will leave about one-third of the appropriation for further 

 prosecution of the experiment. 



From the brief time allowed, it will be impossible for me to do 

 more in this report than to give an outline of the experiments which 

 I have repeated and recorded during the past year. Their full detail 

 and explanation will form a volume replete with interesting scien- 

 tific matter, and require much time and labour. 



The first principal experiments were made with a small trial en- 

 gine, built expressly for the purpose, and Math the utmost care in 

 reference to mechanical accuracy. Attached to this was a dyna- 

 mometer of new construction, and admirably adapted to the purpose. 

 This was invented by my principal engineer, and measured in a 

 most satisfactory manner the dynamic power of the engine at any 

 given velocity — a great desideratum in estimating this new power. 

 With this trial engine the following important questions were 

 tested : — 



1. The dynamic values of different qualities of soft iron. 



2. The dynamic values of steel — hard and soft. 



3. The dynamic value of cast iron. 



The statical values of all these varieties were tested by a separate 

 apparatus constructed for the purpose, called the axial galvanometer. 

 Twelve varieties in all were tested, and were in bars of uniform size, 

 one foot in length, and one inch in diameter, and it was found that 

 the statical and dynamic properties corresponded. 



