264 Mr. E. M. Clarke's Description of 



discovery, and furnished my machines with two armatures, 

 thereby being enabled to give the separate effects of quantity 

 and intensity to the fullest extent of power that my magnetic 

 battery was capable of supplying. 



Fourth. By my intensity armature (which has 1500 yards 

 of fine insulated copper wire on it) I am enabled to go through 

 the various experiments that are usually performed by a num- 

 ber of separate galvanic plates. The effect this armature pro- 

 duces on the nervous and muscular system is such, that no 

 person out of the hundreds who have tried it could possibly 

 endure the intense agony it is capable of producing ; it is ca- 

 pable also of electrifying the most nervous person without 

 giving them the least uneasiness ; it shows the decomposition 

 of water (the gases can be obtained separately or mixed at 

 pleasure) and also of the neutral salts; it deflects the gold 

 leaves of the electroscope, charges the Leyden jar, and by an 

 arrangement of wires from the mercury box to the magnets a a', 

 the electricity is made distincdy visible, passing from the mag- 

 netic battery to the armature, and by the same arrangement 

 not only shocks, sparks, but also brilliant scintillations of steel 

 can be obtained from a a' . 



Fifth. By my quantity armature, fig. 2, 

 (which has forty yards of thick copper 

 bell-wire, and has twice the weight of 

 iron of the other armature,) I am enabled 

 to go through the various experiments 

 that are usually performed by a single 

 pair of voltaic plates or by a calorimotor, 

 but it will not perform any of the same 

 experiments that can be produced by 

 the intensity armature; it gives large 

 and brilliant sparks, sufficiently so that 

 a person can read small print from the 

 light it produces ; it induces magnetism 

 in the apparatus fig. .5; it ignites gunpow- 

 der and the platina wire of the apparatus fig. 4, 'without the pla- 

 tina 'wire being inclosed i?i a hermetically sealed glass tube ; it de- 

 flagrates gold and silver leaf, and produces brilliant scintilla- 

 tions from a small steel file. The most interesting experi- 

 ment it performs is that of producing rotary motion of the 

 delicately suspended wire frames round the poles of a ver- 

 tical horseshoe magnet. Fig. 6. aa\ a cylindrical horseshoe 

 magnet, on a tripod stand, having levelling screws b b' b" ; c d, 

 improved flood cups ; d d\ rotating wire frames, having two 

 little cups at top to hold a drop of mercury ; e, the connecting 

 fork. When this apparatus is connected with the mercury box 



