96 
MR. H. WILDE’S EXPERIMENTAL RESEARCHES 
31. From an examination of the results of these experiments, it will be seen that when 
the submagnet was in direct contact with the electro-magnet, the force required to 
separate them was very greatly increased ; but the ratio of this increase, as measured by 
the same means as in the former experiments (22), is very considerably diminished ; for 
when one magnet was placed on the cylinder, the addition of a second magnet increased 
the sustaining-power of the electro-magnet by 66'5 lbs., whereas when three magnets 
were placed on the cylinder, the addition of a fourth magnet was only attended by an 
increase of 28 lbs. in its sustaining-power. 
3.2. But the most extraordinary fact brought out in connexion with the latter series of 
experiments, is the development of a much greater amount of magnetism in the electro- 
magnet than that which existed in the permanent magnets employed in exciting it ; for 
while the four permanent magnets on the cylinder were only capable, collectively, of 
sustaining a weight of about 40 lbs., the electro-magnet, as will be seen from the Table, 
would sustain a weight of 178*5 lbs. 
33. In order that this remarkable property might be exhibited in a more striking 
manner, a large electro-magnet was constructed by screwing into a heavy iron block, 6 
inches in thickness, two cylinders of wrought iron 24 inches in length and 3|- inches in 
diameter. Round each of these cylinders an insulated strand of copper wires, each 950 
feet in length and 015 of an inch in diameter, was wound from end to end of the cylin- 
ders in several concentric layers, and the two electro-helices were coupled up so as to 
form one continuous helix 1900 feet in length. The cylindrical poles of the electro- 
magnet were 8-| inches distant from centre to centre, and were furnished with a suitable 
submagnet, which was connected by means of a link with a strong lever, for the purpose 
of measuring the amount of force necessary to separate the submagnet from the electro- 
magnet. 
34. When the four permanent magnets (20) were placed on the cylinder of the mag- 
neto-electric machine, and the electricity from it was transmitted through the electro- 
magnetic helices, a weight of not less than 1088 lbs. was required to overcome the 
attractive force of the electro-magnet, or twenty-seven times the weight which the four 
permanent magnets used in exciting it were collectively able to sustain. It will, however, 
be shown hereafter (77) that this difference between the sustaining-power of a perma- 
nent magnet and that of an electro-magnet excited through its agency, great as it is, is 
very far from reaching the limits to which it can be carried. 
35. The question now arose, how the results obtained from these experiments were to 
be reconciled with the principle of the conservation of force, since it is now generally 
held by physicists that the calorific, magnetic, and other properties of the electric circuit 
are correlated, both in direction and amount ; and to admit the coexistence of any one of 
these properties along with the others in a greater or less degree, under like conditions, 
would involve the idea of the miraculous or the paradoxical. 
36. In experimenting with the magneto-electric machine, it was found that the dead 
point of the armature, or that position during its revolution in which no electricity is 
