Page:Popular Science Monthly Volume 63.djvu/403

Rh for a primary classification, or one which will divide individual records into a large number of sets, as described above in the case of the other two systems. In the former article in this magazine, I suggested this by applying names to the various areas marked off by the lines of interpretation, and proposed a set of descriptive formulæ based upon these areas to be used in designating the course of the lines. I now wish to substitute for this a numerical system, the presentation of which in

the form of a key explains itself (Fig. 3). In this, each triradius and intermediate area is furnished with a number, the latter being designated by the odd, and the former by the even, numbers, and the course of a given main line may he simply and accurately described by giving the number corresponding to the point at which it terminates. To the extensive outer border where the use of a single number would be often indefinite, three numbers are assigned, 3, 4 and 5, although where complete accuracy is not needed the symbol (for open) may be used, signifying merely that a given line passes out at some point along the free margin between the outer carpal line and the outer digital one of the little finger. Of these three numbers, 4 is used to designate a