18 



LABORATORY MANUAL OF ANTHROPOMETRY 



The parallelograph, the function of which is to accurately delineate 

 the position of the two needles, projected upon the paper, is essentially 

 a diagraph, like the one described below, having two arms ending in 

 points that can be placed, the one exactly above the other, so that, 

 when the upper one touches a certain point the lower one pricks the 

 paper exactly beneath it. When, now, two points upon each needle are 

 thus recorded upon the sheet of paper, the position of each is fixed, and 



FIG. 11. Parallelograph of Martin. (Manufactured by Hermann; Zurich.) 



their projections are drawn by simply connecting the points of each 

 line by means of a ruler. The angle is then measured by a protractor. 



The parallelograph consists essentially of a vertical rod, rising from 

 the center of an iron tripod, paralleled by a rod of smaller caliber, arising 

 from one leg of the tripod base, and fixed immovably to the first at about 

 3 cm. distant. The larger rod bears two freely movable sockets, con- 

 trolled by binding screws each bearing a horizontal steel needle, each 

 of which may be pushed back and forth through its socket, also controlled 

 by screws. As the needles are graduated the two can be pushed out to 



