10 



To lift 100,00c ,000 lbs. of water by the Japanese method would cost in wages 

 0.0000 436 senx 100,000,000 =yen 43.6, that is 145 times as much as the above 

 engine. 



In tbe larger mines in Europe and Amerfci, it is not an uncommon thing to 

 lift 1,000 gallons per minute. 



Suppose that tliis quantity was to be lifted 1,000 feet, then the cost by the 



Japanese method would amount to : 



. , 0.0000 436x1000x1000x10 . oa 



per minute = 4.3b yen ; 



1 100 J 



per day = 6,278.40 „ ; 



per year =2,291,616.00 „ ; 



While the cost in using the above engine would be : 



. , 0.0000000 3x1000x1000x10 Ano 



per minute — - =0.03 yen ; 



1 100 J ' 



per day =43.20 „ ; 



per year =15,268.00 „ ; 



It is needless to remark, that to this cost must be added interest and amor- 

 tisation for the engine and for the shaft-sinking, as well as expenses to attendants 

 and repairs ; the example suffices to prove, that with the Japanese method 

 it is quite impossible to work on a large scale, and this, if for no other reason, 

 because it is scarcely feasible to procure the space required for such an enor- 

 mous number of pumps. 



Supposing a pump, working day and night, to make on an average 10 strokes 



per minute; then will during that time 10x2=S0 gallons of water be lifted 5.2 



feet high. To lift 1,000 gallons to the same height, would consequently require 



1,000 , n T 



— - — =50 Japanese pumps. 



If each pump with its attendant requires a space of 9 square feet, then the 

 pump-slope aloue must have an area of 50x9 =450 square feet, and to lift the 



water 1,000 feet would require X50 = 8,770 pumps, and with 8 hours' 



0.2 



shifts 26,310 laborers. 



Instead of the pumps as described above, an arrangement is used in some 

 places, where the water has only to be lifted to an inconsiderable height, con- 

 sisting in a bucket, hanging at a straw-rope, which is carried over a roll and is 

 raised by coolies, who harness themselves to the rope. 



VENTILATION. 



No machinery whatsoever is employed for ventilation ; by brattices, however, 

 it is sought to regulate the direction of the air-current. The upper adit in a 



