February io, 1893.] 



SCIENCE. 



79 



vexity, which is always posterior, is in tliis case much shorter in 

 proportioQ. The temporal fossa, as also the surface for the mus- 

 cular insertions, are extensive. The pterygoid surface is not so 

 large as in the Suidae. The glenoid fossa is slightly concave, but 

 not bounded externally by a continuation of the jugal. The con- 

 dyles of the mandible are nearly on a level with the molars, and 

 the coronoid process is small and recurved. The angle is greatly 

 modified for muscnlar attachment. 



In the Hyracoidea, the arch is composed of three bones, of 

 which the jugal is the most important. Resting anteriorly upon 

 the maxilla, the jugal sends backwards a process to form the ex- 

 ternal boundary of the glenoid fossa. It also sends upwards a 

 post-orbital process to meet a corresponding one from the parietal 

 alone or from the parietal and frontal combined, thus completing 

 the bony orbit. Both horizontal and vertical curvatures are 

 slight. The surface for the temporal muscle is largely developed, 

 while the pterygoid fossse are well marked. The ascending ramus 

 of the mandible is high, and the angle is rounded and projects 

 very much behind the condyle, which last is wide transversely, 

 I and rounded on its external border. The coronoid process is 

 small, slightly recurved, and not on a level with the condylar sur- 

 face. 



In the Proboscidea, the arch is straight and slender and com- 

 posed of three bones. The maxilla forms the interior portion, 

 while the jugal. supported upon the process of the maxilla, meets 

 that of the squamosal in the middle of the arch, and is continued 

 under this as far as the posterior root. This modification is un- 

 like that of any other ungulate. There is a small post- orbital 

 process from the frontal. The temporal surface is extensive, and 

 that of the pterygoid considerable. The ascending ramus of the 

 mandible is high, and the condyle small and round. The coronoid 

 process is compressed, and but little elevated above the molar 

 series. The angle is thickened and rounded posteriorly. 



As has previously been remarked in regard to other orders of 

 the Mammalia, the modifications undergone by the jugal arch in 

 the Ungulata are determined by the development of the mastica- 

 tory muscles. In the Perissodactyla, for example, the sagittal 

 crest, ridges, and extensive parietal surface are correlated with 

 increased insertions of the temporal muscle, while the large, 

 strong, and complicated arch have equal reference to a powerful 

 masseter. So in the Artiodactyla, especially in the Ruminantia, 

 the diminished surface for the temporal, and the smaller, weaker 

 arch, both denote diminished energy in the above muscles, while 

 the enlarged pterygoid muscular insertions show that the required 

 action has been provided in another direction. As Professor Cope 

 has shown, " Forms which move the lower jaw transversely have 

 the temporal muscles inversely as the extent of the lateral excur- 

 sions of the jaw. Hence these muscles have a diminished size in 

 such forms as the Ruminants, and are widely separated." 



The singular fact that the Tylopoda alone of the selenodont 

 Artiodactyla possess the sagittal crest is explained by Professor 

 Cope, by the presence of canine teeth, which are used as weapons 

 of offence and defence, and which demand large development of 

 the temporal muscles. Moreover, this group retains the primitive 

 form of the molar series, which is below and posterior to the 

 ^•ertical line of the orbit, while in the Bovidse it is anterior. 



EARLY METHODS OF BORING. 



BY JOSEPH D. MCGUIEE, SMITHSONIAN INSTITUTION, WASHINGTON, D. 0. 



In the process of recent investigations at the National Museum 

 into early methods of boring as practised by ditferent races, the 

 writer thought that the similarity existing between the Esqui- 

 maux toggle or two-handed strap-drill, and practically the same 

 implement used by the ancient Greeks and Hindus, and also the 

 resemblance between the bow-drill used by the early Egyptians 

 and the same tool used by American Indians could not fail to 

 interest those concerned in early methods of boring. 



There is an Egyptian fresco in the Royal Museum of Berlin 

 representing a workman with a bow-drill boring a hole in the 

 bottom of a chair, and the only difference between the drill he is 

 using and those in the National Museum collection, especially 



from the Eskimoin area, is that the Egyptian bow appears much 

 longer than the same tool used by our Indians.' 



There is much in a comparison of these drills that is of interest 

 regarding the evolution of the implement and the possibility of 

 independent invention. The toggle or two-handed drill consists 

 of a shaft a foot or more in length, a head-piece or bearing of 

 woo 1 or ivory, with often a stone socket for the drill-shaft to re- 

 volve in at the top. This socket-piece is held by the one work- 

 ing it between his teeth, and thus kept in position. The shaft is 

 revolved by means of a narrow strap of leather wrapped once 

 around it. On the ends of the thong are tied pieces of wood or 

 bone by which the operator pulls the strap alternately to the right 

 and to the left, thereby revolving the drill, which by downward 

 pressure on the socket-piece is prevented from slipping aside. 



In the ninth book of the Odessey, Ulysses describes how he 

 and his companions, imprisoned in a cave, bored out the eye of 

 Polyphemus (Cowper's translation.) 



" They grasping the sharp stake of olive wood, 

 Infixed it in his eye, myself advanced 

 To a superior stand, twirled it about. 

 As a shipwright with his wimble bores 

 Tough oaken timber, placed on either side 

 Below, his fellow artists strain the thong 

 Alternate, and the restless iron spins, 

 3o, grasping hard the fire-pointed stake. 

 We twirl' d it in his eye; the bubbling blood 

 Boil'd round about the brand." 

 The bow-drill used by the Zuni and other American tribes is 

 an immense improvement on the above, for the thong is attached 

 to a bow woi'ked with the right hand, and the head-piece is held 

 by the left, thus saving the jar to the head and teeth, which 

 with the toggle drill was considerable. 



LETTERS TO THE EDITOR. 



^♦* Correspondents are requested to be as brief as possible. The loriter's name 

 is in all cases required as proof of good faith. 



On request in advance^ one hundred copies of the number containing hin 

 communication will be furnished free io any correspondent. 



The editor will be glad to publish any queries consonant with the character 

 of the journal. 



Confusion in Weights and Measures. 



The remarks of Professor W. P. Mason on "Confusion in 

 Weights and Measures" in Science for Dec. 23, 1892, are interest- 

 ing and timely. A few erroneous statements which they contain 

 serve only to emphasize the fact that the system of weights and 

 measures in customary use is so confusing, so unscientific, and, 

 in some instances, apparently so contradictory that it is difficult 

 to write of it, even briefly, without falling into error. It may be 

 useful to the readers of Science to have some of these errors cor- 

 rected and also to be furnished with a brief statement of the 

 existing condition of the question of standards in the United 

 States. 



Professor Mason's difiBculty in ascertaining the number of 

 grains in a gallon of water at 60° F. is a very natural one, and 

 one not likely to disappear in the near future. The United States 

 gallon is a measure of capacity and not of mass. It contains 231 

 cubic inches. The mass of this volume of water at any given 

 temperature can only be determined by experiment, and an ac- 

 curate determination is exceedingly difficult. All results must 

 be regarded a< approximations, and variation among them means 

 no more than variation among published values of other physical 

 constants, which are determined by experiment, but can never 

 be fixed by legislation. It has always been customary in the 

 United States Office of Weights and Measures, as indeed it may 

 be regarded as almost necessary, to adjust the volume of a capacity 

 standard by ascertaining the mass of water which it will hold 

 under certain conditions of temperature and pressure. But this 

 is merely a matter of convenience ; the gallon is by definition 231 

 cubic inches, and the bushel is 2150.42 cubic inches, and when it 

 is desired to ascertain the mass of a gallon of water one must 

 select that value of the density of water which one thinks the 



I Lepslub, Kong'l. Museum, Abthell. der Aegypt. Altertbumer, Berlin, ISoS, 

 tafel X. 



