MEASUREMENTS 



279 



first to show the use that could be made of the graphic method 

 to register the efforts of the workman's muscles on his tools. 



210. Use o! the "Cabrouet" and the Wheelbarrow. ( l ) The 

 cdbrouet possesses two wheels, which maintain its lateral equi- 

 librium (fig. 170), and these wheels have a small diameter, which 

 requires the man holding the handles to 

 bend his arms very little, the horizontal 

 component of his effort being thus re- 

 duced ( 12), although the equilibrium is 

 stable. 



In the wheelbarrow, on the contrary, 

 there is one wheel of larger diameter 

 (fig. 171). The lateral equilibrium is 

 therefore unstable, and the effort of 

 support is greater, but the effort in the 

 direction of the movement has a greater 

 horizontal component. The cabrouet is 

 designed to transport heavy weights, 

 generally in single pieces, whilst the 

 wheelbarrow is used to transport divided 

 objects, such as stones, sand, gravel, 

 earth, mortar and other materials of 

 construction. The former of these 

 objects is heavy, and its handling often 

 requires two or three men. The latter 



is of an average weight of 30 kilogrammes, a capacity of -fa to -fa 



of a cubic metre, and one man handles it. 



F.G. 170. 



Cabrouet. 



m. 



Wheelbarrow. 



The muscular efforts to be registered are exerted perpendicularly 

 to the handles, to support the load, and parallel to the handles 

 to give the tractive force or the pressure necessary to move the 

 vehicle. 



(*) A. Imbert (Bulletin de I' Inspection du Travail, No. 5, 1905 ; Nos. 

 1 and 2, 1909 ; Revue d'Hygiene et de Police Sanitaire, vol. xxxi., 1909, 

 No. 8). 



