INDUSTRIAL LABOUR 403 



a spring balance was 16 kg. ; 120 buckets were lifted at a speed 

 of -2 metres per second. The work done was therefore : 



37 X 16 x 120 = 71,000 kilogrammetres approximately^ 1 ) 



This leads to an effective duration of six hours. The resistant 

 work due to the descent of the empty buckets, added to the 

 motor work, brings the total to 80,000 kilogrammetres. 



If, on the contrary, a man lifts a weight of 6 kilogrammes at 

 a speed of 0-75 m., Navier found that he could work for 10 hours 

 and produce 162,000 kilogrammetres, that is, double the quantity 

 above. 



6 X 0-75 x 3,600 x 10 = 162, 000 kilogrammetres. 



Drawing water is a primitive operation which is hardly ever 

 done by hand now, and it is also very troublesome. A man 

 drawing water from a tank by means of buckets or tubs, without 

 using a rope and a pulley, only produces 45,000 to 50,000 kilo- 

 grammetres per 8-hour day.( 2 ) By using a scoop, notably the 

 Dutch scoop (see 228) he will produce in the same time 100,000 

 to 120,000 kilogrammetres. ( 3 ) 



A bucket worked by a cord coiled round a windlass will allow 

 work to be done to the amount of 150,000 to 160,000 kilogram- 

 metres. ( 4 ) 



With an ordinary hand pump, a man can give a useful output 

 of 150,000 kgm. per day for 10 hours. Armand Gautier ( 5 ) esti- 

 mated that the corresponding output of muscular work was 

 260,000 kgm. Under very favourable conditions the average 

 effort and speed are 13 kg. and -6 metres respectively. 



309. The Use of the Hammer. Hubert investigated the work 

 done in the use of a hammer at varying speeds and amplitudes 

 of movement. 



The hammer used weighed 7-065 kg. When it was swung 

 through a complete circle the workman could strike 1,690 blows 

 per diem, an output of 65,000 kilogrammetres. When the 

 hammer was swung through an arc of a circle only, and at a lesser 

 speed, 2,560 blows could be struck per diem and the corresponding 

 output of work was 67,000 kilogrammetres (see para. 230 for the 

 method of calculation). Unfortunately no accurate observations 

 were made as to the effect of various shapes and weights of 

 hammers and the speeds at which they were swung. Neverthe- 



( x ) Loc. cit. 



( 2 ) Perronnet. 



( 3 ) Various- observers (Belidor, Perronnet, d'Aubuisson). 



( 4 ) D'Aubuisson. 



( 6 ) See 136 above. 



