MK.MOllJS OF TIIK NATIONAL ACADEMY Ol' SCI KNi.UiS. Hu 



{luidaiici' has bocii the oontonr of tho processus auditorius or tympanic bone. Where this was 

 complete in its ui)per portion, as it rarely is in luau even in the lower races, we liad no tronble in 

 establishinjj our point. Where a good vestige of the npiier i»art remained, not too far out of 

 jilace, we were contented to take such vestige for our guide; but where a large segment of the 

 btine was completely missing we Joined the upper horns of the remaining portion by means of a 

 pencil mark <lescribe(l as ilircctly as possible from one horn to the other on the roof of the meatus 

 and to<ik the highest point of this arched line for <mr landmark. In leveling the skull for the 

 German horizontal idaiie and in taking the auricular heights we felt less hesitancy in depending 

 on this guiding point than in taking vertical arcs. Here it was most doubtful. 



Table i is intended not only to answer the purposes of the i)resent investigation, but possibly to 

 serve as a model for futuie catalogues which may be issued i>y the Surgeon General's Oflice. It has 

 been designed with a view of economizing spiR-e and making reference easy. The jieculiarities of 

 its plan require little exi>lanation. On the tirst i)age of the table and on its duplicate fly-leaf we 

 have given a condensed dcsciiption or indication of each measurement, index, or other item suHi- 

 cient, we believe, for ready reference. In order to get each description within the si)ace of one line 

 we have rarely used the exact woi-ds of the original authors. For the measurement of the German 

 anthropologists we have been especially compelled to reject the circumlocutions of the Frankfort 

 agreement in describing guiding marks and have adopted instead the specific terminology of 

 craniometric science. '-Frankfort," in the table, denotes tiiat the preceding rule is to be found, 

 in substance, in the Frankfort agreement.* "Topinaid" denotes that it is to be found iu the 

 work of this author already refci red to. The number or letter which follows either of these names 

 corresponds with that given to the item by the quoted authority; thus "Frankfort 1" refer.s to 

 the tirst measurement of the Frankfort agreement. Feeling that our brief references to rules 

 might often be insiitlicient for those who had not at hand copies of the oft-quoted Frankfort agree- 

 meut and of the rules of Topinard, we have suj)plied these iu Appendices A aud B of this work. 



\\ 3. THE PICTL'KES OF THE 8KULES. 



The outline tracings of the skulls shown in plates 1 to 54, inclusive, are reductions to half 

 size, made by means of a i^antograph from orthogonal or geometric drawings. 



It seems proper that we should here describe the a()paratus and the method iu use for the 

 past five years in the Army Medical Museum,* by whicih these orthogonal tracings were made, 

 since both seem to ditfer in many respects from those in use elsewhere, as far as we may judge 

 from published descriptions. 



Fig. i.'.'i represents the complete apparatus in use. It consists of a frame (a, a, a), inside of 

 which is an open box (b) nearly filled with dry sharp sand (so arranged that it may be raised and 

 lowered by means of a lever (c), a movable and adjustable mounted pin (d), an ordinary car- 

 penter's or draughtsman's square, and a tracer of i)eculiar construction, which has been named the 

 periglyph (e). The frame is surmounted by a movable plate of glass, thinly varnished on both 

 sides to receive the tracing. 



The periglyph is shown reduced in Fig. 24. It consists of a standard (a), a base {b) (both 

 made i>referably of vulcanite or hard wood), supi)orted by two paddc^l iK)ints (c), and by the sharp 

 steel style (<l), which makes the tracing; vertically above the extreme point of the style is a piu 

 hole on an adjustable arm (e). 



In other laboratories they use diopters, somewhat similar to (his instniinent in appearance, 

 with which the outline is drawn by means of a pen or pencil held in hand. It needs but a single 

 trial to convince one that GUI' instrument, with its fixed steel tracer, is vastly more reliable and 

 convenient. Of course the steel point would not trace on plain gla.ss as the pen does; the thin 

 coat of varnish renders the use of the style practicable. 



• Veretiindigung iiber ein gcniuinsanics cranioinetrisches Verfahren ; .\rchiv fiir Anthropologic, Bd. xv, Braun- 

 Bchweig, 1884, pp. 1-8. (See Appeiulix B.) 



t\V. .\lArrilKWS: Apjiaratua for tracing orthogonal projections of the skull, in the I'niteil States Army Medical 

 Mn.>ieiiin. .lonriial <>f Anatomy and Physiology, vol. xxi, London. 18SG-'87. pp. 12-1.'.. 



