ScJ>L 2, 1 875 J 



NATURE 



369 



feet. The body was then probably covered with bark, or 

 skins of animals. Of course the decomposition would 

 go on very rapidly, and soon no trace remain except the 

 bones and stone implements ; then the weapons only. 

 My reason for believing these graves to be "surface" 

 burials is in consideration of the fact that the inhumed 

 weapons and discoloured dirt are only from three to six 

 inches beneath the sod, and this accumulation of soil is 

 that arising from the annual decay of the preceding sum- 

 mer's foliage, coupled with the dust that would naturally 

 gather around any object lying on the ground. The 

 graves such as I have described, too, are only to be found 

 on the slopes of grassy hill-sides that as yet have not 

 been disturbed by the plough. 1 have never seen such a 

 grave in a ploughed field. Such have been long ob- 

 literated ; and the relics now found in fields may or may 

 not be those that were buried with their prehistoric 

 owners. 



In conclusion, then, seeing that the custom of scalping 

 was not introduced with a knowledge of metals, but pre- 

 ceded it, it is certain that some stone implement was 

 used ; and if in a large series of cutting tools we find 

 some that bear resemblance to the modern form, then it 

 is fair to presume that these, and these principally if 

 not wholly, were those formerly in use. 



A few words concerning this custom of scalping : is it 

 peculiarly North American? I should be much pleased 

 to learn from some correspondent of Nature what other 

 races, if any, have the same practice among them. Inas- 

 much as the Indian custom required of every warrior 

 incontestable proof of his success in battle or in single 

 combat, and considering that a warrior would frequently 

 attack singly some member of a hostile tribe (See Catlin's 

 "North American Indians"), it seems quite a natural 

 method of showing beyond doubt that the claimant had 

 indeed killed his foe. To produce any portion of 

 another's clothing, or his weapons, would not prove the 

 enemy to have been killed ; to produce his scalp shows 

 that such was certainly the case, as the instances of sur- 

 vival after scalping are too few to be considered. Did 

 the custom originate in North America, or was it brought 

 from beyond our borders ? 



Chas. C. Abbott 



Trenton, New Jersey, Aug. 7 



THE SLIDING SEAT FORESHADOWED 



IT is a curious and suggestive fact that nearly all the 

 most ingenious and important mechanical inventions 

 find their representatives in the human frame ; conse- 

 quently, the more we investigate the wonderful mecha- 

 nism of man's body, the more insight may we expect to 

 get into the principles necessary for the most perfect 

 adaptation of means to ends. Whether we take the lever, 

 the pulley, the inclined plane, the spiral or the curved 

 spring, the arch, or any other simple uncomplicated con- 

 trivance adapted with a view^ to securing strength, or 

 motion, or elasticity, we find it represented in animal 

 mechanics, and arranged sometimes simply, sometimes 

 in a more complex form, in a manner and with a result 

 far more wonderful than ever produced from the most 

 ingenious conceptions, of man's brain. 



Of late years the application of the sliding seat to 

 rowing has attracted considerable attention, and although 

 it is beyond the purpose of this paper to consider fully 

 the advantages gained by its application, it will, I think, 

 be necessary to make some reference to what appear to 

 be its principles before we inquire whether it can be 

 traced as existing in certain of the joints. 



In the mechanics of rowing we may look upon the hips 

 and spinal column as theoretically a firm, unyielding 

 lever (Fig. 3, s), since it is knit together by the power of 

 the muscles in a man thoroughly trained. The object of 

 this fixedness is evidently to avoid the loss of power and 



time which would occur if parts had to be strung together 

 preparatory to the pull as the oar catches the water. 

 This spinal lever has its fulcrum at what we call the 

 tuberosities of the ischia (/), or in other words at the points 

 of contact of the body with the seat, and the motive power 

 is placed in the muscles of the back and those of the 

 thigh. The weight to be moved will be acted upon 



Fig. I —Sitting at rest. Showing tip ef shoulder behind the line from 

 mastoid process to hip. 



through the arms at the junction of the upper extremities 

 with the spinal lever. 



As the body moves forwards, the lever formed by the 

 spine rotates round the tuberosities which constitute 

 the fulcrum, and which slide forward at the same time. 

 The knees are consequently slightly bent or separated. 

 As the oar catches the water the body is brought back to 

 the perpendicular by the action of the muscles of the back 

 and those of the thigh, and the lower end of the lever is 

 at the same time carried bodily back a distance of about 

 eight inches. 



The whole principle appears to be that of a sliding 

 fulcrum, and the peculiar result seems to be that a greater 

 reach is given with less bending forward of the body ; for 

 to obtain the same length of stroke the body must either 

 be bent forward at a much more acute angle or carried 

 back beyond the perpendicular. An increased bending 



Fig. 2. — Forward movement in rowing, showing tip of shoulder far in front 

 of the line from mastoid process to hip. 



forwards, it must be borne in mind, must interfere with 

 the respiration in a long-continued strain as in a race, and 

 therefore with the staying powers of the individual. 



If, on the other hand, the body be carried backwards 

 beyond the perpendicular, the power of recovery is dimi- 

 nished, and far greater work is thrown upon the muscles 

 of the trunk and lower limbs. 



