TRAXSACTIONS OF SECTION E. 949 



and greatly restricted the researclies of the expedition. A means of communica- 

 tion would be afibrded by the system of electric balloon sif^nalling invented by 

 the author, adopted for war signalling purposes by the British, Belgian, and 

 Italian Governments, and lately adapted to the wants of Arctic and Antarctic 

 exploration. Signalling with flag or lantern from the car of an ordinary captive 

 balloon, worked from the deck of a ship, is possible, but such a metliod necessitates 

 a large balloon with its cumbersome accessories, and is therefore iuipracticable in 

 Arctic expeditions. In electric balloon signalling, the signaller and most of the 

 apparatus remain on the ground or deck of ship. Since the weight of the car, 

 signaller, and apparatus is abolished, the balloon can be of such a moderate size 

 as to be practical. The apparatus consists of a balloon made of a translucent 

 material and filled with hydrogen or coal gas. In the balloon are placed several 

 incandescent electric lamps in metallic circuit with a source of electricity on the 

 ground or deck of ship. In the circuit on the deck is an apparatus for making 

 and breaking contact rapidly. By varying the duration of the flashes of light 

 in the balloon, it is possible to signal according to the Morse code. In the 

 signalling key there are carbon contacts, renewable when worn away by sparking. 

 The key is placed on a switch board, which is provided with a means of turning 

 the current on to the lamps in the balloon, either through the key or directly for 

 continuous illumination. The speed of signalling depends entirely upon the 

 thickness of the carbon filaments in the lamps. 



The material selected for making electric balloons that are designed for Arctic 

 work is goldbeaters' skin, which is light, strong, and retentive of hydrogen. The 

 smallest size goldbeaters' skin balloon that would lift the lamps, and a sufficient 

 quantity of cable to be useful, is seven feet in diameter, and having a capacity of 

 150 cubic feet. It takes little over one tube to fill it. 



The electric incandescent lamps inside the balloon are supported one above the 

 other on a holder made like a ladder. This form of ladder is convenient for 

 admission into the narrow neck of the balloon. 



The electric cable combines lightness, flexibility, and current capacity, being 

 made of strands of copper, both leads being enclosed in one waterproofed outer 

 insulation. The source of electric power for lighting the lamps in the balloon 

 would probably be the dynamo, with which every future exploring vessel will 

 probably be provided, and which can be efficiently worked with wind or hand- 

 power. If a balloon and accessories is taken from the ship by an excursion 

 party, light and portable storage cells can be used. The gas for filling the 

 balloons can be compressed in steel cylinders, or a portable apparatus can be 

 used for making the hydrogen on the spot. 



This system of signalling makes the signallers fairly independent of the con- 

 figuration of the country. An electric balloon ascending from the deck of the 

 exploring vessel would not only act as a beacon guide to exploring parties, 

 but would flash signals relating to the drift of the ship or any other desirable 

 communication. If an exploring party could take another balloon with them, 

 complete intercourse could be established. If the ' Fram ' had had an electric 

 balloon afloat, it would have been probably seen by Dr. Nausen when he was 

 returning from his journey north, and possibly a long and perilous march might 

 have been avoided. An electric balloon would have been an important addi- 

 tion to an Arctic station such as Elmwood. 



The electric balloon has been successfully manipulated, not only in calm and 

 fair weather, but in half a gale, a snowstorm and mist ; signals have been read and 

 answered in spite of these adverse atmospherical conditions. Arctic records, how- 

 ever, include a large proportion of still and clear weather. 



Continuously illuminated, and sent up a short distance from the ship, the 

 balloon would also be serviceable as a light for working parties, because of the 

 diflPusion of light from the large surface. 



Hegarding the distance to which signals may be transmitted, it is reasonable 

 to expect that, given a sufficient altitude, a high candle power, and a clear atmo- 

 sphere, through a telescope the flashes would be visible some 80 or even 100 

 miles. 



