The Form
In the theoretic part of this work we emphasized the word form, representing the body as a whole and embodying the conception of relationship between the proportions of the body, tending to determine the morphological individuality.
From the normal point of view the two individualities which are most interesting and worthy of comparison are those of the new-born child and the adult (see Fig. 140 and its eloquent testimony). In these two individualities the greatest possible prominence is given to those differences of proportion between bust and limb on which all the various measurements of the form depend: the standing and sitting stature; the total spread of the arms; the weight; the circumference of the thorax (see "Theoretic Lessons on the Form"). With the theory recalled to mind we may now pass on to the practical procedure for obtaining these various measures. Among them the most important is the stature, whose cycle is represented in Fig. 141. The theoretic section of this book devotes special attention to the stature in a separate chapter following that on the Form. It is well to have in mind the general principals before taking up the technique of the separate measurements.
Stature.—The stature is the distance intervening between the plane on which the individual stands in an erect position and the top of his head.
Fig. 140.—New-born child and adult man reduced to the same height and preserving their relative bodily proportions. The head of the new-born child is twice the height of that of the adult and extends downward to the level of the latters's nipples. The pubes of the adult correspond to the navel of the new-born child; and the pubes of the child to the middle of the adult's thigh.
Technical Procedure.—It is necessary to know how to place the subject in an erect position, heels together and toes turned out, shoulders square, arms pendent, head orientated, i.e., occipital point touching the wall, gaze horizontal.
In measuring the individual stature it is customary to use an instrument called an anthropometer (Fig. 142).
It consists of a horizontal board on which the subject stands, a stationary vertical rod marked with the metric scale against which the subject rests his back, and another small movable rod perpendicular to the first and projecting forward from it; this is lowered until it is tangent to the apex of the cranium; and the scale upon the upright rod gives the number corresponding to the stature.
Fig. 141.—Diagram representing the cycle of stature of man (unbroken line) and woman (dotted line), from birth to the end of life.
Certain anthropologists are now trying to perfect the anthropometer (Mosso's school). And, indeed, how is it possible to bring the entire person posteriorly in contact with the vertical rod of the anthropometer? The rod is straight while the body follows the curves of the vertebral column and the gluteus muscles. Accordingly, Professor Monti, an assistant to Professor Mosso, has proposed a new anthropometer which, in place of the single rod at the back, has a pair of rods, so that the more prominent portions of the body may occupy the intermediate space; a similar anthropometer was already in use for measuring kyphotics.
Fig. 142.—Anthropometer.
Fig. 143.—A square.
At the present day there are exceedingly complicated and accurate anthropometers which comprise, in addition, instruments for obtaining various other measurements, such as the thoracic and cephalic perimeters, etc. But these are very costly and not practical for use in schools. Their use is confined chiefly to medical clinics, as, for example, Viola's anthropometer, which is used in Professor De Giovanni's clinic.
Broca recommends to travelers an anthropometer consisting of a graduated rod with a movable index attached. By means of this a series of distances from the ground can be measured, and consequently various partial heights of the body, from the ground to the top of the head, from the ground to the chin, to the pubis, to the knee, etc., but grave errors may be committed and its use is not advisable so long as we have within reach a universal anthropometer.
The universal anthropometer consists essentially of two planes perpendicular to each other; now we may say that in every room, in the meeting of two planes, the floor and the wall, we have an anthropometer. There is no reason why we should not make use of this simple means! Placing the child in an erect position with the body touching the wall throughout its whole length, we place a perfectly horizontal rod tangent to the top of the head, we make a mark upon the wall, and then with a millimetric measure we take the distance between the mark and the floor, and this gives us the stature. Two difficulties are met with, first, that of holding the rod horizontally on the top of the head, and secondly, that of measuring the distance in a perfectly vertical line. In the first difficulty a carpenter's square may help us or, if there is a school of manual training within convenient reach it is easy to have a little instrument constructed (Fig. 143) consisting of two planes perpendicular to each other, one of which should be held tangent to the head while the other is pressed against the wall (carpenter's square).
As regards the vertical measurement, a plumb line may be used, but it is more practical to trace upon the wall that we mean to use for such measurements, a design consisting of a vertical line on which a mark may be made at the height of one metre from the floor in order to simplify the task of measuring.
It is better if the millimetric tape is made of metal, so that it will not vary in length; but even a tailor's measure of waxed tape may answer the purpose if it is new and has been tested with a metallic measure or an accurate metre rule.
The height of the stature is taken without the shoes, and it is necessary to state at what hour of the day the measurement is made, because in the morning we are taller (though by only a few millimetres) than we are in the evening. The stature may also be taken in a recumbent position (length of body), and in this case will be longer by about one centimetre.
Consequently in giving the measure of stature it is necessary to state in what position the subject was placed, by what method the measurement was taken (whether with an anthropometer or not) and at what hour of the day the measurement was made.
It is not necessary to say that the subject was required to remove his shoes, since that is taken for granted.
Sitting Stature.—Besides the stature taken on foot, the sitting stature (height of bust) is also taken by an analogous process. It is the distance between the plane on which the individual is seated and the vertex of his head. The subject should be seated upon a wooden bench having a horizontal plane and should place his back in contact with the wall; just as in the case of the preceding measure the shoes had to be removed, in the present case the clothing is discarded, leaving only the light underwear (Fig. 144). With the aid of the square we find the point corresponding to the vertex of the head and with the millimetric measure we obtain the distance on the wall between this point and the plane of the bench.
Fig. 144—(1) Sitting stature. (2) Standing stature.
(Method of taking measurements with the Anthropometer.)
Index of Stature.—We know that these two measures are extremely important for ascertaining the type of stature, i.e., macroscelia and brachyscelia, determined by the proportion between the sitting stature and the total stature reduced to a scale of 100, that is, the relation of the bust to the total height of the individual. Let us remember in this connection that the bust should be a 52d or 53d part of the total stature and that below 52 down to 50, it is macroscelous, and that above 53, up to 55, it is brachyscelous.
Having obtained the two numbers corresponding to the two statures, e.g., stature 1.60 m., bust 0.85 m., how are we to find out the percentual relation between the two measurements? First, we form an equation: 85:160 = x:100.
from which we obtain x = (100×85)/160 = 53
This stature is of the normal average type, that is, it is mesatiscelous; but the mesatiscelia is high (in comparison with the other measurement that is also mesatiscelous, namely, 52), in other words, it is brachy-mesatiscelous.
Note the formula which gives us the value of x. If we substitute general symbols in place of the concrete values, we may say that x is equal to one hundred times the lesser measurement (m) divided by the greater measurement (M). If, in place of x, we substitute I, signifying index, we may draw up the following general formula of indices:
I = (100×m)/M
This formula of relations between measurements is of wide application in anthropology and is fundamental. Indices of every measurement are sought for. The one given above is the index of stature, and it determines the type of stature. All the other indices are calculated by similar procedure.
Fig. 145.—Method of measuring the total spread of arms.
Total Spread of the Arms.—This measurement is taken quite simply. The subject must place himself with his arms outstretched in a horizontal direction and on a level with his shoulders. The measurement corresponds to the distance intervening in a horizontal line from the tip of one middle finger to the other (Fig. 145). A specially constructed anthropometer may be used for this measurement. It has a long horizontal rod adjustable perpendicularly, so that it may be placed on a level with the shoulders of the subject to be measured. This rod forms a cross with the other vertical rod with which the subject should be in contact. The arms are then extended along the cross rod which is marked with a millimetric scale. But this greatly complicates the anthropometer, and hardly any anthropometer possesses this attachment. This measure may be successfully taken with the very simple aid of the wall. The only difficulty offered is that of securing a perfectly horizontal position for the arms. For this purpose horizontal lines, which either happen by chance to be upon the wall or which may be drawn on purpose, will be of assistance. In order to have guiding lines suited to different statures, several horizontal lines may be drawn intersecting the vertical line already traced for guidance of the millimetric tape measure used in taking the stature.
Thoracic Perimeter.—The thoracic perimeter is taken on the nude thorax, in an erect position and with the arms hanging beside the bust, by applying the millimetric measure in such a way that its upper margin passes just below the nipples. The tape measure should completely encircle the thorax in a horizontal plane passing through the mammary papillæ. Since the thorax is in constant motion, we must observe the oscillations of the tape measure and obtain the average; or else we may take the measurements during the state of expiration (repose). In giving the figure it is necessary to specify the procedure followed.
Vital Index. Index of Life.—Index of life is the name given to the proportion between the stature and the thoracic perimeter. It ought to be equal to 50, i.e., Tp = S/2
Vi = (100×Tp)/S = 50 (normal).
Weight.—The weight of an individual is taken by means of ordinary scales. In order to obtain the weight of the nude person, the clothing may be weighed separately and their weight subtracted from the total weight of the clothed person. The weight should be taken before eating, in order that unassimilated alimentary substances may not alter the real weight of the subject. If this method cannot be rigorously followed out, it should be specified how much clothing the subject retained, whether he had eaten, etc.
Ponderal Index.—Stature and weight are the most synthetic and comprehensive measurements of the form. But we need a clear proportion between these two measures to tell us whether an individual weighs more or less relatively to his stature. It may happen, for instance, that a stout person of short stature actually weighs less than another person who is tall and thin; but relatively to his stature he may on the contrary be heavier, that is, he may have a higher ponderal index. A robust and plump child will weigh in an absolute sense less than an adult who is extremely thin and emaciated; but relatively to the mass of his body he weighs more. Now this relative weight or index of weight (ponderal index) gives us precisely this idea of embonpoint, of the more or less flourishing state of nutrition in which an individual happens to be. But linear measurements such as the stature cannot be compared with volumetric measurements, such as the weight. Hence it is necessary to reduce the volumetric measure—the weight—to a linear measure, which is done by extracting the cube root from the number representing the weight. Then the root of the weight may be compared to the stature reduced to a scale of 100. By forming a general proportion, in which W represents the weight of a given individual, and S the corresponding figure of his stature, we obtain:
S:∛(W)::100:x (where x represents the ponderal index)
hence Pi = (100×∛(W))/S
The application of this formula would necessitate some rather complicated calculations, which it would be inconvenient to have to repeat for a large number of subjects.
But there are tables of calculations already compiled, which are due to Livi, and which are given, together with other tables, in Livi's own work, Anthropometry (Hoepli). These are numerical tables, to be read in the same manner as tables of logarithms. At the top, in a horizontal direction, the stature is given in centimetres, while in the vertical column the weight is given in kilograms. The calculation of all the ponderal indices has been worked out, in relation to every possible stature and weight. If we look up the ponderal index corresponding to the figures already cited in illustration (see p. ([182])), we find that for the adult the Pi = 23.6, and for the child the Pi = 27.4; i.e., considered relatively the child weighs more in the given case. This is the true and accurate technical method of finding the relative proportion between weight and stature.
Accordingly, we have now learned to take all the measurements relative to the form, to calculate from them the more important indices (or proportions), such as the index of stature, the index of life, and the ponderal index. We have also learned to understand and to consult the tables of anthropological calculations.