Steampunk Prime_ A Vintage Steampunk Reader - Mike Ashley [72]
VIII.
SEA-SIGNALLING — THE FINAL FLIGHT
We had noticed at times when the sky was cloudy, both by day and by night, certain periodic flashes of light appearing on the clouds in quick succession. Electra told me that these were caused by the system of cloud-telegraphy now in use; and to anyone familiar with the Morse alphabet, as I was, it was easy to read the messages so flashed about the heavens, though I could not understand those that were in cipher. Most of them were of a general nature, and had nothing to do with us. But at intervals we observed that telegraphic inquiries were being made on the clouds about our party, and that certain persons whom we were not able to identify — most of them signing these communications with numerals instead of names — were answering those inquiries. I may as well jot down in this place the information I gathered as to the mode of signalling by cloud-flash and by other new methods.
Powerful electric rays are, by means of lenses, brought to thin pencils of intense light. A single one of these is then projected upward against a cloud. A controlling shutter in the path of the beam of light interrupts it at will, so that it may be made to show long or short flashes on the clouds. Words are thus illuminated in the sky, and made to shine in the zenith repeatedly, until an answering reflection is obtained. The chief use of this cloud-telegraphy is, of course, on the sea between ships and “steamers” (as they are still called, notwithstanding that they do not use steam) or for airboats. Conversation may be carried on in this way between vessels many miles apart; and a message received by one can be transmitted to others, so that inquiries and replies fly all around the globe and to remote parts of ocean. The system was found useful in those later voyages to the North Pole, which have not been followed up since a general exploration of the open Arctic Sea was effected. It has also saved many lives, prevented collisions, and caught many fugitive criminals. Sailing vessels are provided with a water-paddle to drive the necessary electric generating mechanism for signaling when the ship is in motion.
In some of the much-traveled sea regions, another method of communication is used for the daytime. A sail-cloth, woven with metallic wire, is hung between the tips of two masts, and is connected to a special electric generating apparatus, producing waves of extreme sharpness and great intensity that follow each other at the rate of seven hundred per second. An electric stress thus propagated to infinite distance is; at moderate distances, strong enough to be collected by the metalized sail of another vessel. One ship, for example, wishes to know whether there is another within the area of signaling, but out of sight. The musical note formed by electric inductive waves is set going, and, by means of a key, is stopped and started again at will. Other vessels in the area have watchers who, at intervals, listen to an exquisitely sensitive telephone made selectively sensitive to waves of exactly seven hundred per second. This is brought about by a tuning-fork attachment to the diaphragm, tuned exactly to respond to waves of that rate; hence, although the part of the waves collected by the sail-cloth is many million times less than could be gathered if it were close to the signaling ship, yet the tuning-fork collects successive waves until the amplexitude of vibration is sufficient to cause audibility. The signaling current is continuous for several seconds. Then the transmitting vessel stops it and connects the sail with its receiving apparatus to listen