JoLY — Oil the Investigation of the Deep-sea Deposits. 257 



'in raising the filled receptacle to the surface that work has to be expended 

 equivalent to what has been done at the bottom of the sea. The elevation 

 of the land above the floor of the ocean and the relatively low density of 

 water supply the conditions essential to the localization of power in the 

 manner proposed. 



The power available is very considerable. Let us suppose a sufficiently 

 strong cylinder fitted with a piston 1 square centimetre in area, and having 

 a stroke of, say, 30 centimetres. The volume swept out in one stroke is 

 30 cubic centimetres. Now at 1000 fathoms the pressure is about 220 kilo- 

 grams per square centimetre. Hence if the piston describes one stroke under 

 the influence of this pressure, the force on it is 220 kilograms (484 lbs.), and 

 the work done 66 x 10* gram- centimetres (484 foot-pounds about). At 

 500 fathoms the work done in one stroke is about half this, and in 

 2000 fathoms it is, of course, about double this. 



In the next place, let us assume that the receptacle into which the water 

 is discharged holds 10 litres. The volume of water entering it at each 

 stroke is 30 cos. Hence the number of strokes required to fill the receptacle 

 is 333. In practice the force at 1000 fathoms on the piston imagined above 

 would be found inconveniently large. A piston or plunger of one-half a 

 square centimetre in area, used along with the imagined receptacle, would 

 give 666 strokes at a force of 110 kilos. (242 lbs.). If one stroke is 

 accomplished in one second, this amounts to about 0'4 horse-power for 

 eleven minutes. A receptacle one cubic foot (28'3 litres) in volume would 

 enable such an engine to run for thirty-one minutes. It is evident, then, 

 that quite small receptacles will suffice to work an engine developing 

 considerable power, the motion of which is sustained over a period sufficient 

 to carry out useful drilling or boring operations. For the greatest depths 

 the volume of the receptacle may be diminished and the piston area 

 correspondingly reduced. These conditions are convenient, as they involve 

 for the greater depths a lighter machine. 



A working drawing of a hydraulic engine suitable for the conditions 

 described, and intended to bore into the soft sediments and oozes on the 

 ocean-floor, accompanies this paper (Plate XIX). A description of this will 

 now be given. 



The plan shows four cylinders A, B, C, D. Each couple of cylinders, 

 A-B, C-D, constitutes a separate engine. The fittings permit the ready 

 suppression and removal of one of the engines when, at considerable depths, 

 the one engine is sufficient to operate the drill. Or we may, in this way, 

 secure a more sustained drilling action ; the time required to fill the 

 receptacle being, of course, halved when two engines are used. 



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