THE SUBMARINE BOAT. 723 



heavier than fresh air, since it is carbonic acid, and not a mechanical 

 mixture of nitrogen and oxygen. By simply keeping in the upper 



portion of the vessel the crow would almost have comparatively fresh 

 air nearly the entire time. Quite a different tale would have been told 

 if the Fulton had been made to get under way. She would then have 

 had to use her electric motors, and a drain would have been made upon 

 her storage batteries. From this cause noxious vapors would have 

 been generated and the various compartments would have been unin- 

 habitable after a fraction of the period that would have been required 

 to make the boat unendurable from the human exhalation. 



It is on record that one individual in a New England town several 

 months ago actually entered a metallic burial casket and was sealed 

 up for a period of one hour. He simply demanded thatthe glass plate 

 over the head piece be not covered and thatthe individuals conducting 

 the test should look through the head plate at intervals, so that lie could 

 smile at them. It was rather a ghastly test, but it was a successful 

 one, although the individual undergoing the operation lost 5 pounds 

 in the undertaking. In this test the man did not probably have -1 

 cubic feet of air to draw upon. To appreciate exactly what was 

 undergone by those who went down in the ]-'iilt<>i^ the crew had sim- 

 ply to enter a hermeticall} 7 sealed room of the dimensions recorded. 

 It did require physical courage, however, for eight men to remain in 

 a submarine boat under those circumstances, since derangements were 

 possible which might have prevented the boat rising. 



COMPASS UNRELIABLE IN BOATS OF DIVING TYPE. 



For the past ten years the advocates of the submarine have been 

 telling at intervals of a discovery whereby the submarine boat can 

 be navigated with precision when under way. One of the ablest 

 compass experts in the Navy has given special attention to this matter. 

 In the investigation of this subject he found that a reputable adjuster 

 of compasses from New York, who corrected the compass of this sub- 

 marine boat, furnished the Holland Company with nine different devia- 

 tion tables, to be used as a disposition of the disturbing torpedoes 

 necessitated. It is his opinion that, in general, the compass on the 

 submarine boat must be regarded as more or less unreliable. Placed 

 near to or within an iron or steel mass, it is subjected not only to 

 large disturbing influences, but also to a serious decrease of directive 

 force. Any change in magnetic conditions within the vessel itself, as 

 well as accidental extraneous influences, will attack the weakened 

 compass with a force inversely proportional to the directive force. 

 The inclination of the boats of the diving type is a great disturber of 

 the compass, and must be very carefully corrected. This expert 

 maintains that the magnetic compass in a submarine boat will be so 

 unreliable that the craft will frequently be compelled to rise to the 



