INDUSTRIAL LABOUR 429 



In the construction of embankments, the shovel is swung to a 

 height of nearly 1-6 metres and the load of earth is consequently 

 reduced to between 1 J and 2 kilogrammes. From 15 to 20 cubic 

 metres can thus be shifted in 10 hours. Taking the higher figure 

 in each case, the number of spadefuls was 



20 x 1898 = 18,980. 



2 



and the work done : 



18,980 X 1-6 X 3-7 = 112,362 kgm. 

 (taking the weight of the spade itself as 1-7 kg. as before.) 



In spite of the length of the working day, this result is far from 

 being the maximum obtainable, owing to the same load of earth 

 lifted by each spadeful. Owing to the considerable amplitude of 

 the movements much fatigue is caused to the muscles of the legs 

 and the loins. The value of the muscular work is, therefore, 

 very high, and, in addition, the muscles of the lower limbs are, 

 to some extent, utilised. 



326. The Action of the Legs. Use of the Wheelbarrow and 

 Stone Truck.- Imbert investigated these operations frcm the 

 mechancial and muscular point of view and not from the energetic 

 aspect. His results are most interesting. 



The transport of cut stones for the mason's use is often carried 

 out by the stone truck (cdbrouet) sometimes known as a "devil." 

 In its use the work of the legs is no less important than that of 

 the arms.f 1 ) and the mechanical actions of the labourer consist 

 in loading the truck, pulling or 'pushing it to its destination and 

 unloading it. The methods given above ( 210) were employed 

 to register the efforts normally exerted on the handles, in support, 

 loading and unloading, and those exerted in the direction of the 

 handles in pushing. 



A load of 60 kg. required an exercise of force by the right leg 

 equivalent to that needed to mount a step 12 cm. high ( 2 ) and also 

 called for an expenditure of force, by the extensor muscles of the 

 trunk and upper members, equal to about 30 kg. This last result 

 shows that such work is rather too heavy for youths of 15 or 16. 

 The work is also less fatiguing for the tall than the short. 



Imbert found that the work done in conveying 62 loads (of 

 60 kg. each) per hour over a distance of 24 metres along a smooth 

 horizontal surface of concrete was certainly not less than equi- 

 valent to the following. 



1 . An ascent of a stairway with 62 steps, i.e., an effort of be- 

 tween 25 and 30 kg. repeated 62 times. 



( 1 ) Imbert and Mistre, extract from the Bulletin de I' Inspection du Travail, 

 1905, No. 5, pp. 15-32). 



( 2 ) This effort is needed to balance the load on the truck. The com- 

 parison thereof with the effort in mounting a step is hardly satisfactory. 



