2 DR. FARADAY’S EXPERI.VJENT AL RESEARCHES IN ELECTRICITY. (SERIES XXIV.) 
(as to motion) being the neutral condition. The final nnchangeabiiity of gravity did 
not seem affected by such an assumption ; for the acting bodies when at rest would 
ever have the same relation to each other, and it would only be at the times of mo- 
tion to and fro that any results related to electricity could be expected. Such 
results, if possible, could only be exceedingly small ; but, if possible, i. e. if true, no 
terms could exaggerate the value of the relation they would establish. 
2704. The thought on which the experiments were founded was, that, as two 
bodies moved towards each other by the force of gravity, currents of electricity might 
be developed either in them or in the surrounding matter in one direction ; and that 
as they were by extra force moved from each other against the power of gravitation, 
the opposite currents might be produced. Also, that these currents would have rela- 
tion to the line of approach and recession, and not to space generally, so that two 
bodies approaching would have currents in the opposite direction as to space gene- 
rally, but the same as to the direction of their motion along the line joining them. 
It Mull be unnecessary to go further into the suppositions which arose concerning 
these points, or regarding the effect of forced motions either coinciding with, or 
across the direction of the earth’s gravitation, and many other matters, than to say 
that, as the effect looked for was exceedingly small, so no hope was entertained of 
any result except by means of the gravitation of the earth. The earth was therefore 
made to be the one body, and the indicating mass of matter to be experimented with 
the other. 
2705. First of all, a body, which was to be allowed to fall, was surrounded by a 
helix, and then its effect in falling sought for. Now a body may either fall with a helix 
or tlirough a helix. Covered copper wire, to the amount of 350 feet in length, was 
made into a hollow cylindrical helix, about 4 inches long, its internal diameter being 
1 inch and its external diameter 2 inches. It was attached to a line running upon 
an easy pulley, so that it could be raised 36 feet, and then allowed to fall with an 
accelerated velocity on to a very soft cushion, its axis remaining vertical the whole 
time. Long covered wires were made fast to its two extremities, and these being 
twisted round each other, were attached to a very delicate galvanometer, placed 
about 50 feet aside from the line of fall, and on a level midway with its course. The 
accuracy of the connection and the direction of the set of the needle, were then both 
ascertained by the introduction of a feeble thermo-electric combination into the cur- 
rent. Such a helix, either in rising or falling, can produce no deviation at the galva- 
nometer by any current due to the magnetism of the earth ; for as it remains parallel 
to itself during tlie fall, so the lines of equal magnetic force, which being parallel to 
the dip, are intersected by the wire convolutions of the descending helix, are cut 
witli an equal velocity on both sides of the helix, and consequently no effect of mag- 
neto-electric induction is produced. Neither in rising nor in falling did this helix 
present any trace of action at the galvanometer ; whether the connection with the gal- 
vanometer was continued the whole tirne, or whetiier it was cut off just before the 
