THE IMPENETRABLE SEA 



recent history when related to the sea explorations of 

 primitive man, but old enough, when considered with 

 other historical facts, to set us wondering at the naivete 

 of Dr. Halley's statements. 



The ancient Greeks used many products which could 

 only have been obtained from the sea-beds of the coastal 

 waters. A certain shellfish contributed a dye for the Im- 

 perial purple. Roman soldiers used sponges as canteens 

 on their marches. A sponge soaked in vinegar was offered 

 to Christ on the cross. Shells from the shores, numbers of 

 which could only have been obtained by divers, were 

 built into medieval cathedrals, particularly those of the 

 great Tridacna clam, which were often used for fonts. 

 Dr. Halley must surely have known some of these 

 historical facts and of the exploits of pearl divers ; and 

 other naked underwater swimmers of his own times. Yet 

 he specifically states the limit of underwater endurance 

 * 'ordinarily" as half a minute, and of experienced divers 

 as two minutes. 



The main problem of naked diving without appliances 

 was always that of holding the breath long enough to 

 accomplish some task under water or on the sea-bed. 

 Pearl divers, from earliest times, have always been able 

 to stay under water for periods exceeding three minutes, 

 and there are numerous well-authenticated instances of 

 divers going down to a hundred feet or more, and re- 

 maining under for longer periods. 



One of the most remarkable cases in recent times — on 

 account of the depth attained, apart from the period of 

 endurance — is that of a Greek sponge diver named 

 Stotti Georghios. Wearing no breathing apparatus, fins 

 or eyeglasses (and not even carrying a stone or a sponge) 

 he went down to a depth of two hundred feet in 1 9 1 3 to 

 attach a line to the lost anchor of the Italian battleship 

 Regina Margharita. At that depth the pressure on his lungs 

 was enormous — they were squeezed by seven atmospheres 

 of pressure, which should have been enough to collapse 



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