THE WORLD'S ADVANCE 



which it is exhausted. Now our naval 

 authorities have introduced a modifica- 

 tion. The British investigators found 

 that most of the air pumps for divers 

 were quite incapable of giving them the 

 full and abundant supply needful when 

 working at depths of 150 feet and more. 

 The exhaust from the helmet was apt 

 to be too feeble to take up and drive out 

 the gathering carbon dioxide exhaled by 

 the diver. In order to offset this danger 

 and to make the diver independent of 

 toilsomely-driven hand pumps, a steam 

 or electrically-operated compressor was 

 employed and the air stored in a suitable 

 reservoir. 



The diver's air tube was connected to 

 this tank with a reducing valve inter- 

 posed the tank being charged at a pres- 

 sure considerably in excess of that re- 

 quired at the operating depths. In this 

 way, the underwater worker had com- 

 plete control of his air supply by simply 

 turning the little valve in front of him 

 on his suit, and the people on the tender 

 had only to see that the tank was kept 

 duly loaded. Another innovation is the 

 hospital or recompression lock. As you 

 possibly know, the caisson workers on the 

 shore now have a hospital lock where 

 they can undergo recompression and then 

 decompression after coming out from 

 their underground chambers, but this has 

 not been applied until recently to the 

 working facilities aboard a salvage craft. 



Ordinarily the diver is brought up to 



within about 50 feet of the surface and 

 then slowly raised at intervals, covering 

 a decompression period of an hour, pos- 

 sibly, if his submergence' has been long 

 and the depth great. In cold water, this 

 is exhausting and adds just so much to 

 the bodily drain already made by his 

 operations on the bottom. To overcome 

 this, a recompression chamber or hospital 

 lock is now utilized, and instead of hold- 

 ing the diver in the chilling water and 

 decompressing him there, he is brought 

 up at a safe speed to the surface and 

 hustled right into the lock where the air 

 pressure is raised to a suitable point. 

 There, his diving dress is removed and 

 dry and warm clothes are put on him, 

 and a cup of beef tea or something of the 

 kind given him. All the while the pres- 

 sure is being systematically lowered and 

 he is able to talk with the attendant and 

 to relax and rest. In this manner the 

 safety of the diver is looked after as was 

 not the case until latterly, and, at the 

 same time, it is found that these deep- 

 water workers can do more than was 

 previously believed possible. Undoubt- 

 edly, divers will soon be able to descend 

 to depths of 300 feet, and this is getting 

 close to the 4OO-foot submergence which 

 the English scientists declared would be 

 possible provided the diver remained 

 there only a short while. The human 

 body is astonishingly adaptable. The 

 only thing is how to humor it and what 

 must be done to avoid abusing it. 



WHALE CUTS OFF SUBMARINE 

 CONNECTION 



A short time ago the cable connection 

 was suddenly cut off between Skagway 

 and Juno, up in the Fairbanks district 

 of Alaska, and for some time the trou- 

 ble could not be located. At last the 

 cableship Burnside found what was 

 wrong. In some inexplicable way a large 

 whale had become entangled with the 

 cable, and the divers from the cable-ship 

 found him with a half -hitch of the cable 

 around his head and lower jaws. They 

 removed the dead whale and re-estab- 

 lished the connection by mending the 

 break in the cable. 



ARMORED CAR THAT CAN BE 

 DRIVEN FROM EITHER END 



Because it is sometimes necessary for 

 an armored motor car to be taken quickly 

 out of a tight corner or narrow lane 

 when it is in action, the designers of the 

 protected fighting autos of the Eaton 

 Motor Machine Gun Battery in the Can- 

 adian army have struck upon the orig- 

 inal and unique arrangement of having a 

 second steering wheel and an auxiliary 

 set of clutch and brake controls at the 

 rear end of the cars so that the machines 

 may be driven backward as easily and 

 as speedily as in the forward direction. 

 A mechanical difficulty lies in the fact, 



