Powers of Electro-Magnetism, Steam, and Horses. 449 



Having placed the two straight steel magnets (each of which 

 was 4 feet 4 inches long, 4 to 5 inches square, and had poles 

 of 1\ square inches surface) side by side, in a horizontal 

 position, and with two of their poles connected by a suitable 

 armature, we placed the hollow electro-magnetic armature on 

 the axis of a revolving apparatus, in such a position that the 

 poles of the armature could revolve at the distance of about 

 ^th of an inch from the poles of the steel magnets. The coils 

 were arranged for quantity, and connected by means of a 

 proper " commutator " with platinum plates (each exposing 

 an active surface of 5 or 6 square inches) immersed in a dilute 

 solution of sulphuric acid. The maximum amount of decom- 

 position was effected when the armature revolved 500 times 

 per minute. At this velocity f ths of a cubic inch of the mixed 

 gases were collected per minute. 



Having removed the hollow armature, we now fastened the 

 Jlat semicircular armature upon the axis. When this arma- 

 ture, with its four coils arranged for quantity, was rotated at 

 the rate of 500 revolutions per minute, we collected as much 

 as 1*4 cubic inch of the mixed gases per minute. With the 

 same velocity of rotation, two inches of steel wire, g^th of an 

 inch thick, were raised to a bright red heat; and one inch of 

 the same kind of wire was fused. 



Great as the above effects undoubtedly are, in comparison 

 with previously recorded results, we expect to be able to aug- 

 ment them very much by causing the armatures to revolve 

 opposite the true poles of the magnets, and not, as heretofore, 

 opposite their ends. It is proper also to observe, that on ac- 

 count of the imperfect hardness of many of the steel bars*, 

 the magnets did not possess one quarter of the power due to 

 Dr. Scoresby's principle of construction. We have not, how- 

 ever, hitherto cared to reconstruct the apparatus, because our 

 principal object in the present research was to make experi- 

 ments with the machine working as an engine, for which pur- 

 pose the magnets were quite powerful enough. 



The battery employed for working the machine as an engine, 

 consisted of three cells of Daniell's constant arrangement. In 

 each cell the copper element exposed an active surface of two 



* The bars of which the magnetic apparatus was constructed were of 

 various lengths, but of otherwise uniform dimensions, viz. \\ inch broad 

 and ^th of an inch thick. The thickness and mass were found too great 

 for effective hardening, at least for obtaining a degree of hardness capable 

 of sustaining the severity of the magnetic test. (Economy and facility of 

 arrangement were the reasons for adopting this construction, rather than 

 the more certain and effective one of hard thin plates, described by Dr. 

 Scoresby in his " Magnetical Investigations." 



