16 LABORATORY MANUAL OF ANTHROPOMETRY 



and is thus provided with two sliding cross rods, graduated in milli- 

 meters; the upper rod is fixed, the lower movable. As the entire appara- 

 tus may be raised or lowered in its standard, the fixed upper rod can be 

 readily placed at the upper limit of the line to be tested, while by moving 

 the lower one up or down, and by pushing it in or out, its point may be 

 adjusted to the lower terminus. This line is thus recorded upon the 

 goniometer by the two points of the cross rods, and may be read off upon 

 a protractor, by so placing the long needle that its lower thin edge 

 exactly crosses on the lower rod the degree indicated upon the upper one 

 by the little mark in the center. 



Fig. 9. — Attachable goniometer of Mollison used upon the scale rod. (After Mollison.) 



Aside from this the upright standard of the instrument, which may be 

 raised and lowered in a slot, is also graduated to millimeters and can 

 thus record differences in level. With the graduating of the cross rods 

 also, there are numerous other uses to which this instrument may be put 

 aside from the measurement of profile angles. Yet, these other uses are 

 generally as well performed, and more conveniently, by such simpler 

 instruments as the clamp-on form of the goniometer, and thus the 

 more complicated form is probably destined to be gradually superseded. 



Parallelograph. — The torsion, or twist, in the shaft of a long bone, as 

 shown by a superposition of the axes of certain features at its two ends, 

 is a very special, yet often an extremely important, character. This is 



