354: ^'- Francis Galion [May 25, 



outline of the face itself. The measurable distances between the 

 profiles of diiierent jDersous are small, but the available measui-es are 

 much more numerous than might have been expected, and their varia- 

 tions are more independent of one another than those of the limbs. 

 I suspect that measures of the profile may be nearly as trustworthy 

 as those of the limbs for approximate identification, that is, for 

 excluding a very large proportion of persons from the possibility of 

 being mistaken for the one whose measurements are given. The 

 measurement of a profile enables us to use a mechanical selector for 

 finding those in a large standard collection to which they nearly 

 correspond. From the selection thus made, the eye could easily 

 make a further selection of those that suited best in other respects. 

 A mechanical selector also enables us to quickly build up a standard 

 collection step by step, by telling us whether or no each fresh set of 

 measures falls within the limits of any of those already collected. If 

 it does, we know that it is already provided for ; if not, a new card 

 must be added to the collection. There will be no fear of duplica- 

 tions, as every freshly-added standard will difler from all its pre- 

 decessors by more than the specified range of permitted dificreuces. 



As regards the most convenient measurements to be applied to a 

 profile fur use with the selector, I am unable as yet to speak decidedly. 

 If we are dealing merely with a black silhouette, such as 

 Fig. 8. the shadow cast on a wall by a small and brilliant light, the 

 best line from which to measure seems to be B C in Fig. 8 ; 

 namely, that which touches both the concavity of the notch 

 between the brow and nose, and the convexity of the chin. 

 B It is not difficult to frame illustrated instructions to ex- 

 plain w^hat should be done in the cases where no line can be 

 drawn that strictly fulfils these conditions. I have taken 

 a considerable number of measures from the line that touches 



do the brow and chin, but am now inclined to prefer that 

 L which I have just desL-ribed. A sharp unit of measurement 

 * is given by the distance between this line and another 

 ^\ drawn parallel to it just touching the nose, as at N in the 

 figure. A small uncertainty in the direction of B C has but 

 a very trifling efiect on this distance. By dividing the in- 

 terval between these parallel lines into four parts, and draw- 

 ing a line through the thii-d of the divisions, parallel to B C, we obtain 

 the two important points of reference, M and E. M is a particularly 

 well-defined point, from which is determined by drop2)ing a per- 

 pendicular from M upon B C. O seems the best of all points from 

 which to measure. It is excellently placed for defining the shape 

 and position of the notch between the nose and the upper lip, which 

 is perhaps the most distinctive feature in the profile. O L can 

 be determined with some precision ; B and C are but coarse 

 measurements. 



In addition to these and other obvious measiu*es, such as one or 

 more to define the projection of the lips, it would be well to measure 



N 





