"Yes, we know all that," shouted the voice, "but what we don't know is this: the cockle of the ear belongs to the species of the Helix, and the little bones near the drum are exactly like the animal in Limnaeus stagnalis, and that's printed in a book." Victor, who realised at once that the voice belonged to a thought-reader, shouted back brutally, but without showing the least surprise:
These continuous currents at the poles, which bewilder our compasses, must possess an extraordinary influence. And it would suffice that a block of iron should be subjected to their action for it to be changed into a magnet of power proportioned to the intensity of the current, to the number of turns of the electric helix, and to the square root of the diameter of the block of magnetized iron.
The formation of the helix on the flat side of the stick apparently shows us that the continued striving of the tip to curl itself closely inwards gives the force which drags the tendril round a smooth cylindrical stick.
Swarms of them preceded us for one or two miles, from tree to tree, making the air ring with their incessant screams, and then returning in long flights to their favourite haunts, from which we had disturbed them. We saw four kangaroos; and shot some bronze-winged pigeons; in the crop of one I found a small Helix with a long spire, a form I do not remember ever having seen before in the colony.
The principle has already been explained namely, the alternate rising and falling of an iron rod within a helix through which an electro-magnetic current is made to pass: when the current is on, the rod rises, and remains, as it were, self-suspended, equidistant from all parts of the surrounding helix; and falls as soon as the current ceases by breaking contact with the battery.
In another experiment he employs a simple hollow coil, or helix, of insulated wire whose ends are connected with a galvanometer. On suddenly thrusting one end of a straight cylindrical magnet into the axis of the helix, the deflection of the galvanometer needle showed the presence of an electric current in the helix.
But whilst the voltaic current was continuing to pass through the one helix, no galvanometrical appearances of any effect like induction upon the other helix could be perceived, although the active power of the battery was proved to be great by its heating the whole of its own helix, and by the brilliancy of the discharge when made through charcoal.
Out of the hundred shells twenty-seven recovered. The presence of an operculum seems to have been of importance, as out of twelve specimens of Cyclostoma elegans, which is thus furnished, eleven revived. It is remarkable, seeing how well the Helix pomatia resisted with me the salt-water, that not one of fifty-four specimens belonging to four other species of Helix tried by Aucapitaine recovered.
E. Ray Lankester informs me of another case in a chimpanzee in the gardens at Hamburg. The helix obviously consists of the extreme margin of the ear folded inwards; and this folding appears to be in some manner connected with the whole external ear being permanently pressed backwards. See also some remarks, and the drawings of the ears of the Lemuroidea, in Messrs. On the other hand, Prof.
When the conducting-cords are not attached to the machine, or when the communication between the cords is not complete, if the machine be running, the circuit is then composed of the battery fluid, the platina plate, the posts, the connecting-wires, which unite the battery with the helix, the helical wires, and their appendages for the vibrating action.