THE EXTERNAL ENVIRONMENT 259 



and that the influence of rhythm is the best of all when it. comes 

 from the movements of the tools alone ? 



191. The influence of noise, shocks, and vibrations is entirely 

 different. No kind of human activity can be regulated by them 

 because of their lack of periodicity. The effects of vibration 

 and shock are inconvenient and even harmful. Thus the vibra- 

 tion and jolting of motor omnibuses is trying to the drivers, and 

 especially to the conductors, since they are standing for con- 

 siderable periods. The result is muscular fatigue and nervous 

 exhaustion, to which latter the incessant noise no doubt contri- 

 butes. In workshops, badly balanced machinery, running at 

 high speeds, is a fruitful source of vibration, affecting both persons 

 and buildings in the vicinity. The natural elasticity of the 

 human frame cannot completely deaden vibration. 



Although familiarity greatly diminishes the sensitiveness to 

 vibration and noise, yet both are unfavourable influences in the 

 workshop, and it is very desirable to avoid them as far as possible. 



192. The Influence of Tools. The output of a workman is 

 obviously affected by the quality of the tools with which he 

 works. Dupin remarked, in 1825, that the superiority of the 

 British workman was due to the high quality of his tool equip- 

 ment. 



The weight of hand tools is also a matter of importance. To 

 permit of rapidity of movement and maximum output, the tool 

 must not exceed a certain weight. The proper weight for each 

 trade or occupation is a matter to be decided by experiment, in 

 which the age and physique of the worker must have due con- 

 sideration. 



In fact, the whole outfit of the workshop, both machine and 

 hand tools, should be designed on natural lines so as not to 

 interfere with the speed of the movements nor cause anything 

 which is not strictly profitable to the work, nor entail interrup- 

 tions other than those of the rest intervals ; The useful efforts 

 must be reduced to a minimum, and useless contractions of the 

 muscles must be suppressed. Thus the transport of earth in a 

 wheelbarrow with only one wheel causes oscillations which bring 

 about rapid fatigue ; therefore a wheelbarrow with two wheels 

 should be employed. 



Study and knowledge must assert themselves in proportion to 

 the needs of the scientific organisation of industrial labour, in 

 order to substitute rigorous methods for the guesses of empiricism. 

 An eminent American engineer, Frederick Taylor, f 1 ) applied the 

 above principles in engineering workshops, where, thanks to the 



(*) Frederick Winslow Taylor, Principles of Scientific Organisation of the 

 Workshops ; and Publication of the Review of Metalurgy, 1907. 



