LOCOMOTION 



387 



PIG. 272 



Relations between output per kilogrammetre, speed, 

 and amount of work done. 



297. Early Observations. The observations of Borda (at 

 Teneriffe) of Coulomb, Hachette and Navier have only a historic 

 interest. Coignet's (*) observations, however, merit some atten- 

 tion. When supervising the construction of field works at Vin- 

 cennes, that officer introduced an arrangement by which the 

 labourers mounted the banks by ladders, but descended by means 

 of counterbalanced platforms so that the men's weight in de- 

 scending drew up loaded barrows. He observed that 310 ascents 

 were made per diem, the height being 13 metres and the speed 

 18 metres. He estimated the maximum daily work done by a 

 labourer weighing 70 kg., as : 



70 X 310 X 13 = 282.100 kilogrammetres. 



Coignet (Memorial de I'Officier de Genie, No. 12, p. 285, 1835. 



