IN MAGNETISM AND ELECTRICITY. 
91 
great law under which the apparent anomaly may disappear, and by which all these 
various phenomena presented to us shall become one.” 
6. As the investigations which led to the paradoxical conclusions enunciated above 
(4) were not originally intended for publication, but were undertaken for my own 
instruction, I find that it will be much more convenient to describe the experimental 
results in a more methodical manner than that in which they were obtained. 
7. The numerical determinations, derived from the experiments to be described, will 
be given with sufficient exactitude to allow of a comparison being made between them 
and those of other experimentalists. Other quantitative determinations will, for the 
present purpose, be sufficiently expressed by the terms “ greater ” and “ less,” as attention 
will be chiefly confined to a description of well-defined phenomenal effects. 
8. Though I make use of certain conventional terms in connexion with the subject of 
these researches, it is not thence to be inferred that I hold to the opinion that specific 
entities distinct from ordinary matter are concerned in the production of phenomena of 
any kind whatever. 
9. The apparatus with which the experiments were made is shown in Plate VI. figs. 1-10. 
Two blocks of cast iron, A, A, of the form shown in figs. 1, 2, 3, and two pieces of brass, 
B, B, of the same length as the cast-iron blocks, were bolted together at the top and 
bottom with small brass bolts, in such a manner as to form a compound hollow cylinder 
of brass and iron, hereafter called the magnet-cylinder. A smooth and parallel hole C, 
If inch in diameter, was bored through the magnet-cylinder ; and the thickness of the 
brass packings, B, B, separating the iron sides of the cylinder from one another, was 
three-quarters of an inch, or nearly half the diameter of the hole. Two pillars of 
wrought iron, D, D (fig. 3), were screwed into the cast-iron projections E, E (figs. 1, 2, 3) 
at each end of the magnet-cylinder, for the purpose of holding the cross-heads F, F, 
fig. 3. These cross-heads were made of brass, and were bored out concentrically with 
the hole through the magnet-cylinder, so as to form suitable bearings in which the 
journals of an armature might revolve. 
10. The armature, which was of the same form as that used by Siemens (figs. 4, 5, 6, 7), 
was made of cast iron, and was turned parallel throughout its entire length, and about 
one-twentieth of an inch less in diameter than the hole in the magnet-cylinder, for the 
purpose of allowing it to revolve inside the cylinder in close proximity to it, but without 
touching it. The thickness of the rib G, uniting the segmental sides of the armature 
(figs. 4, 5, 7), was one-quarter of an inch. Two brass disks or caps, H, H', having con- 
centric prolongations for holding the steel journals I, I, were fitted by means of screws, 
one at each end of the armature. A pulley, K, for driving the armature was fixed upon 
the cylindrical axis of the cap H', and upon the axis of the cap H at the other end of 
the armature, a commutator, L, L', of hardened steel was fixed. 
11. About 163 feet of copper wire 0 - 03 of an inch in diameter, insulated with silk, 
was wound upon the armature (fig. 6) in the direction of its length. The inner extre- 
mity of the wire was placed in good metallic contact with the armature, and its outer 
