60 THE LAST CRUISE OF THE CARNEGIE 



demand for electric current is very heavy for such a small vessel. 

 As a matter of fact, a considerable part of the gasoline fuel we 

 carried was devoted to electric requirements. 



Switch-panels for the sonic depth-finder, radio generator, and 

 bronze winch, line the walls. A machine-shop containing a lathe 

 leads off to one side while the photographic dark-room is wedged 

 in between the gasoline-tanks and the battery-recess. A sail- 

 locker and storage space for spare instrumental equipment are 

 also accessible from the engine-room. 



It is always a relief to leave the engine-room, for it is infernally 

 hot. We ascend to the quarter-deck, step down into the waist 

 of the ship on the port side, and enter the radio cabin. A short- 

 wave experimental receiving set, built for us by the United States 

 Naval Research Laboratory, brings us time-signals, weather- 

 reports, and news from home. Our transmitter was powerful 

 enough to keep us in communication with the United States 

 almost every day, through the cooperation of amateurs. Special 

 apparatus for making investigations of radio signal-strength is set 

 up on the work-benches. The equipment is very complete, be- 

 cause the radio operator had a unique opportunity for studying 

 radio conditions at sea; he could correlate variations of signal - 

 intensity with magnetic and atmospheric-electric changes. Regu- 

 lar short-wave schedules gave us information about radio "skip- 

 distances" over the oceans. 



In recent years there has been considerable interest in the so- 

 called "Kennelly-Heaviside conducting layer." This zone, 

 situated some fifty or more miles above the Earth, is thought to 

 be the path by which radio signals travel from place to place. 

 Experiments at the Laboratory of the Department in Washington 

 show that this layer varies in height from time to time, and can 

 be located by "echo-sounding." It is hoped that the radio in- 

 vestigations made on the Carnegie may add some information 

 about this radio zone. 



The American Radio Relay League with headquarters in Hart- 

 ford recommended our first operator, Mr. Jones, and cooperated 

 with us throughout the whole voyage. The value to us cannot 

 be exaggerated of the services rendered by hundreds of amateurs 

 throughout the world. 



