270 



THE HUMAN MOTOR 



Where a is an instrumental co-efficient and b depends on the 

 density of the air. The apparatus must therefore be tried at 

 known speeds, in still air. Given the speeds V 1 and V 2 , for 

 which the corresponding number of revolutions are N x and N 2 

 in the same time, it will follow that: V x = a + bN 1 and V 2 = 

 a _|_ fcN 2 , from which the values of a and b can be deduced. 



There are numbers of types of anemo- 

 meters : those of Casartelli, Biram, Robin- 

 son, Rosenmiiller, Richard, etc. The latest 

 anemometer of Lea-Biran's f 1 ) has a vane 

 wheel, p, operating a pointer which moves 

 over a dial, c, a system of gears reducing 

 the speed of rotation of the pointer, so that 

 it does not make more than 20 revolutions 

 per minute, when the speed of the wind is 

 10 metres (fig. 159). 



If there are N revolutions in t seconds, 

 the speed in metres is given by 

 equation : 



30N 



the 



m. 



V = 



In Robinson's model the vane wheel is formed of hemispherical 

 cups instead of flat vanes ; but the apparatus is too heavy and 

 has too much friction whilst the indications are not accurate. 



Richard's anemometer, like the Biram type, has a very light 

 vane wheel, with aluminium wings ; it indicates the speed of 

 the wind in metres. 



201. Static Elements of the Human Machine : Stature. The 



stature ( 77) is determined by the use of Alphonse Bertillon's 

 methods. ( 2 ) For the total stature the subject, with naked feet, 

 is placed against a vertical wall with the heels together, the 

 head held straight, and looking straight in front of him. A 

 2-metre scale is applied vertically on the wall, from the ground ; 

 a set square is held against it and caused to slide down into con- 

 tact with the top of the head, when the measurement is shown 

 on the scale. It is better to take it twice, and it is especially 

 essential to watch that the subject does not assume bent atti- 

 tudes, hollowing his back, pushing out his stomach or shortening 

 his neck. The feet being flat on the ground, this method gives 

 the whole vertical development (fig. 160). The anthropmetric 

 measurer is easily handled. 



(*) Engineering of 20th Oct. 1911. 



(*) Consult Anthropologie Metrique by Bertillon et Chervin Paris, 1909. 

 We owe the three following illustrations to M. Bertillon 



