Page:Scientific Memoirs, Vol. 1 (1837).djvu/545

Rh upon the latter. But an adhesion which continued after the cessation of the magnetizing currents then contributed to diminish the mechanical effect; whilst in the preceding arrangement the adhesion not only ceased, but to a certain point changed to repulsion, with the same rapidity with which the current, scarcely interrupted an instant by the action of the bascule, precipitated itself (the communication being inverted) into the middle spiral, in a direction contrary to its original one, resuming its ordinary course in the two other spirals.

The motion of the lever and of the regulator, resulting from this arrangement, is perfectly free; at first rather slow, it soon and by degrees acquires the maximum of velocity which the energy of the currents producing it allows of,—a velocity which is afterwards maintained equal to the intensity of the current itself, and as long as the latter remains in action.

I shall say nothing at present respecting some observations which I have on this occasion collected, upon the employment of different acid and saline solutions, and of sea water.

It is not without especial interest that we contemplate these new effects of a force developed in so singular a manner from the masses of bodies; and it is difficult not to be carried away by flattering anticipations respecting the ulterior applications which the acquisition of this mysterious motive force suggests.

The dimensions of the apparatus which has just been described are small, and such as the current produced by fifteen elements of nine square inches can put in motion. The electro-dynamic cylinders, which principally determine the limits of the mechanical effect, are one decimetre in length and a centimetre and a half in diameter; these are surrounded by a wire coiled in a spiral, the length of which is 40 metres, and half a millimetre in diameter. The lever is of wood; the upper and lower arms are respectively 35 and 7 centimetres long; the amplitude of its oscillations is 15°. Lastly, the regulator weighs 2½ kilogrammes; and the total weight of the mechanism is about 5 kilogrammes.

Considerations which readily presented themselves regarding the relations between the maximum of the magneto-mechanic effect of the apparatus and the dimensions of its different parts, have made me think