FOOTNOTES
[3] In 2930, all aircraft engines were operated by radio-power transmitted by senders in various districts. The New York Power House controlled a local district of about two hundred miles radius.
[4] Cylinder records of books which by machinery gave audible rendition, in similar fashion to the radio-phonograph.
[5] The Power House on the Hudson dam was operated by inert machinery and manned entirely by humans—the only place in the city which was so handled. This was because of its extreme importance. The air-power was broadcast from there. Without that power the entire several hundred mile district around New York would be dead. No aircraft could enter, save perhaps some skilfully handled motorless glider, if aided by sufficiently fortuitous air currents. Every surface vehicle used this power, and every sub-sea freighter. The city lights, and every form of city power, were centralized here also, as well as the broadcasting audible and etheric transmitters and receivers. Without the Power House, New York City and all its neighborhood would be inoperative, and cut off from the outside world.
[6] I mentioned the small conning tower on top of the laboratory building and the Robot lookout there with his audible broadcasting.
[7] This was part of Tugh's plan. The broadcast voice was the signal for the uprising in the New York district. This tower broadcaster could only reach the local area, yet ships and land vehicles with Robot operators would doubtless pick it up and relay it further. The mechanical revolt would spread. And on the ships, the airliners and the land vehicles, the Robot operators stirred to sudden frenzy would run amuck. As a matter of fact, there were indeed many accidents to ships and vehicles this night when their operators abruptly went beyond control. The chaos ran around the world like a fire in prairie grass.
[8] The police army had one weapon: a small vibration hand-ray. Its vibrating current beam could, at a distance of ten or twenty feet, reduce a Robot into paralyzed subjection; or, with more intense vibration, burn out the Robot's coils and fuses.
[9] The storage batteries by which the Robot actuating energy was renewed, and the fuses, coils and other appliances necessary to the Robot existence, were all guarded now in the Power House.
[10] As a matter of actuality, Tugh was carrying hidden upon his person a small cylinder and battery of the deadly white-ray. It seems probable that although on the catwalk—having accomplished his purpose of getting within the electrical fortifications of the dam—Tugh had ample opportunity of killing his over-trustful companions with the white-ray, he did not dare use it. The catwalk was too dark for their figures to be visible to the Power House guards; the roar of the spillways drowned their shouts; but had Tugh used the white-ray, its abnormally intense actinic white beam would have raised the alarm which Tugh most of all wanted to avoid.
