6 DR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SEPJES XXIV.) 
Strength to these numbers; and the differences of these currents being continually 
gathered up by the commutators, were made sensible at the galvanometer. This v'as 
rendered manifest by placing the machine so, that though the plane of vibration was 
still vertical, the place of the helix was just under the centre of motion, and the cen- 
tral line of the helix therefore, instead of being vertical, was horizontal. Now the 
convolutions of the helix cut the lines of magnetic force in the most favourable 
manner; and the consequence was that the commutators were not required, for a 
single motion of the helix in one direction was sufficient to show at the galvanometer 
the magneto-electric currents induced. If, on the contrary, the plane of motion was 
made horizontal, then no current was produced by any amount of motion ; for though 
tlie helix was as horizontal as, and not sensibly more so than before, yet the parts of 
the convolutions which intersected the magnetic lines of force (being the upper and 
the lower parts) now moved with exactly equal velocity, and no differential result 
was produced. 
27 16. The former small result (2715.) was therefore probably dependent upon an 
effect of this kind ; and this was confirmed by placing the machine in such a position 
that the axis of the moving copper cylinder and helix should in its medium position 
be parallel to the line of the dip, and then no effect was produced. Other bodies in 
the same position were equally unable to produce any effect. 
2717- Here end my trials for the present. The results are negative. They do not 
shake my strong feeling of the existence of a relation between gravity and electricity, 
though they give no proof that such a relation exists. 
Royal Imtitution, 
July 19, 1850. 
