ANTHBOPOMETRY 39 



certain amount of careful attention, especially on expeditions. They 

 should be well nickeled, to prevent rusting. They must work smoothly 

 but not loosely. The joints and slide boxes should be kept slightly 

 oiled, but so as not to soil the fingers of the operator. All the instru- 

 ments should be periodically tested on standards, which gives the 

 worker due confidence. If a thermometer is used it should be an 

 instrument with plainly legible scale and one which will without fail 

 give the maximum record within five minutes. Rapid thermometers 

 are not especially advantageous, they break more readily, being made 

 of thinner glass. To keep the thermometer clean a small bottle of 

 peroxide or other antiseptic is provided, in which the instrument is 

 kept between use. A towel or two should be kept on hand to clean 

 the instruments as desirable in the course of the procedure. Finally, 

 due attention must be given the instruments in connection with storage 

 in the laboratory between examinations, and in connection with trans- 

 portation. They should have a suitable glass-door case in the labora- 

 tory, and a specially made portable box or case for outside and field 

 work. 



3. A study of landmarks should logically be the next step. Measure- 

 ments, to be strictly comparable, must be taken in a strictly defined 

 way and from or between the same anatomical points. These points, 

 whether on the living or on the skeletal parts are known as the anthro- 

 pometric landmarks, with which the student must become thoroughly 

 acquainted. To facilitate this he should begin with the most needed 

 points on a good series of dry skulls of both sexes and widely differing 

 ages where he may learn their exact location, significance and variation. 

 An additional skull of a young and one of adult anthropoid ape, 

 particularly the chimpanzee, are very useful in this connection. 



From dry material but with this still at hand, the student will pass 

 to the determination of the needed landmarks on living male adults, 

 then on females and finally on children. He should invariably now 

 and even later mark some of the points with an aniline pencil, which 

 will facilitate his measurements. 



4. In the actual practice of measuring, it is necessary to impress the 

 student with the necessity of concentration of his attention on the 

 subject or specimen within his hands and on the scale of his instrument; 

 the holding and handling of the instrument will rapidly become auto- 

 matic. With subject in convenient position, the landmarks deter- 

 mined, and the instruments properly used, everything depends on the 

 accuracy of reading of the scale. More and larger errors probably are 



