Up to this point we have assumed that, while touching two points in the wire, the rest of the circuit is perfectly insulated, so that no current can leak, in other words, that the circuit is nowhere "grounded." If this is not the case we may, under suitable conditions, receive a shock by touching only one point of the wire. This becomes clear by considering the current to leak from another spot of different potential, to pass through the ground and into the body; thus, on touching the wire the body virtually makes a connection between the two points of the circuit. In clear dry weather such leaks are insignificant; but in damp and rainy weather, and with poor insulation, they may rise to such a point at which it would be dangerous to touch the circuit even with one hand, the leaks being sometimes so great as to cause the lamps to burn in a fitful, desultory manner, and to go out entirely.
There is still another factor which enters into the discussion of the danger of electric light wires. This must be looked for in the fact that the physiological effects are greatest at the moment of the opening or the closing of the circuit; or in a closed circuit they are the more marked when the flow of current stops and starts, or diminishes and increases. In dynamo electric machines the current is not absolutely continuous or uniform, since the coils on the armature being separated a distance cause a slight break or diminution of the current between each. This break is so short that it does not interfere with the practical work for lighting; in some constructions, nevertheless, the distances apart is so great that, while not interfering with light, its effects upon the muscles are greatly increased over those of other constructions which give a more uniform current.
All these statements might lead to the conclusion that arc light wires are dangerous under any circumstances; but this is not the case. The first and only requisite is, that they be perfectly insulated. When thus protected accidents from them are impossible, and all mishaps that have occurred through them can be traced directly to the lack of insulation. Nevertheless, we would warn our readers against experimenting upon arc wires by actual trial, because unforeseen conditions might lead to disagreeable results.
ROBERT CAUER'S STATUE OF LORELEI.
The statue of Lorelei, the mythical siren of the Rhine, represented in the annexed cut, which is taken from the Illustrirte Zeitung, was modeled by Robert Cauer, of Kreuglach on the Rhine. He was born at Dresden in 1831, and is the son of the well-known sculptor Emil Cauer, and a brother of the sculptor Karl Cauer.
LORELEI STATUE BY ROBERT CAUER.