A laboratory manual of anthropometry / by Harris H. Wilder.

  • Harris Hawthorne Wilder
Date:
[1920], ©1920
Catalogue details

Licence: Public Domain Mark

Credit: A laboratory manual of anthropometry / by Harris H. Wilder. Source: Wellcome Collection.

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    exactly the same length. When this is done the two are brought per- fectly parallel by swinging them against the smaller of the two parallel uprights. The points of the two needles are now in the proper position the one exactly above the other, but are directed differently, for while the point of the upper needle is directed outwards, as the prolongation of the needle itself, that of the lower is carried upon a secondary piece at right angles to the main needle, and is thus directed downwards, so that it may prick the paper placed beneath the apparatus. To project a given line (here a knitting needle fastened to the bone to be measured with respect to torsion) the point of the upper needle is placed in contact successively with two points on the needle defining the axis to be projected, while the lower needle records the points by making slight punctures in the paper beneath. If any two approximately transverse axes are both projected so that they cross, an angle is formed that can be easily read. In using the parallelograph care must be taken that both transverse needles of the instrument are in contact with the smaller upright, and that they are pushed out equally; as otherwise the points would not lie in the same line vertically. This may be made certain by bringing the upper arm so far down towards the other, that the point of its needle coincides with the median axis of the vertical part of the lower needle. The shape of the upper end of this facilitates this comparison. Volumes.—The principal volumes used by the anthropometrist are those of the cranial cavity and the orbit of the eye, the first one of the very earliest, the other one of the latest of anthropometric data to be developed. For the first, the technique for which is to be found elsewhere, the essential apparatus consists of some medium with which to fill the cavity, such as shot, sand, mustard seed, etc., a graduated cylinder in which to measure the medium, and usually some simple mechanical means to insure a uniformity in pressure during the filling and emptying. A control skull, either an actual skull, or a receptacle of similar shape, of known capacity, is frequently used at short intervals during the work, to see that the measurements are made with a fair amount ol uniformity. Weight—The weight of an object is seldom used in anthropometry except in the case of the entire body. The weight of certain oigans in a perfectly fresh condition, as provided during an autopsy, has also been found of some value, especially in the case of the brain; but the weight of bones depends so much upon their condition, especially with regard to water content, that, except where the condition is absolutely the same, as in comparisons of the weight of the different bones of the same skeleton, such are of no especial value. For all such work any form of reliable scales provided with the metric weights is satisfactory, foi accurate bodil} weight special forms of scales are obtainable, as are used in gymnasiums, hospitals and clinics. To have any anthropometric value the weight of