Jan. 20, 1888.] 



SCIENTIFIC NEVV^S. 



53 



WILL MEN EVER FLY ?-I. 



WILL men ever fly ? 

 That is a question which has attracted the at- 

 tention of mankind for countless ages past, and would 

 yet seem as far as ever from receiving an affirmative 

 answer. We have constructed balloons, and risen to 

 heights at which existence can with difficulty be main- 

 tained. But that, of course, is not flying at all ; neither 

 would be our passage through the air by mechanical 

 agency. And we have striven, but always in vain, to 

 adapt wings, or modifications of wings, to the human 

 frame. 



For, in all attempts of the latter class, the immense 

 difference between the human structure and that of flying 

 animals appears to have been consistently ignored. Ex- 

 perimentalists have gone to work as though the one and 

 only requisite were the possession of wings, altogether 

 forgetting that almost every detail of almost every part of 

 the frame must be altered before those wings could be 

 employed with any chance of success. The lungs must 



their frames when compared with those of their nearest 

 allies, the monkeys, is yet amply sufficient to show us 

 how hopelessly impossible it is that man should ever fly 

 at all. 



I pass by the question of the wings themselves alto- 

 gether. These, in man, would naturally be represented 

 by artificial substitutes, and thus the complete transforma- 

 tion of his arms into organs of flight would not be re- 

 quired. But the muscular system in connection with 

 those limbs, and the bony framework of the shoulders and 

 the chest, would necessarily be greatly changed. So we 

 find in our bat. The shoulder-blades, in the first place, 

 as shown in Fig. i, are large and broad, and are traversed 

 by a deep " keel," for the better attachment of the power- 

 ful wing-muscles. The breast-bone, too, is almost dis- 

 proportionately large and stout, and is keeled in precisely 

 the same manner, while the collar-bone and the ribs are 

 also very strongly and solidly built. The hinder portions 

 of the skeleton, however, upon which the strain of the 

 wing-muscles is not thrown, are strikingly slender and 

 dwarfed, every particle of unnecessary material being 



Fig. I. Skeleton of a Bat. 



be greatly enlarged, the muscular system greatly strength- 

 ened, the skeleton greatly modified, the Vv^eight greatly 

 diminished, the bodily balance completely changed. 

 Could man literally and actually fly, he would be 

 man, physically speaking, no longer, but would differ 

 from the human type at least as greatly as does the bat 

 or the bird. And thus it is that his attempts to furnish 

 himself with artificial wings are ever doomed to 

 failure. 



Let us glance at the structure of the three classes of 

 beings — bats, birds, and insects — to which the power of 

 flight has been granted, passing by such creatures as the 

 flying squirrel, the flying dragon, and the flying fish, 

 which merely skim for limited distances through the air, 

 but do not really fly at all. By this means we shall gain 

 some idea of the alterations which would be necessary in 

 our own frame before we could acquire the enviable 

 faculty in question. 



First, then, as to the bats. 



These are creatures whose powers of flight, albeit 

 amply sufficient for their wants, are not of a very re- 

 markable character ; they lack both the speed and the 

 endurance which characterize so many birds and insects. 

 But the extensive modification which is yet visible in 



removed in order to reduce the weight to the lowest 

 possible degree. 



So with the muscles. Those in the anterior portion 

 are stout and strong, those in the posterior are small and 

 feeble. Power of flight is the paramount necessity, and 

 so to that all else gives way. 



Some kind of a rudder is necessary, for wings alone 

 would be of but little use for purposes of steerage ; and 

 so the wing membrane is brought round behind the body, 

 and supported by the bone of the tail. Further support, 

 however, is required, and so a long and slender bony 

 spur, so to speak, runs from either heel, passes between 

 the upper and lower layers of the wing-membrane, and 

 affords the necessary rigiditj'. 



The lungs, as is only to be expected, occupy a very 

 considerable space, for rapid aerial motion implies a cor- 

 respondingly rapid consumption of oxygen, and a conse- 

 quent increase in the extent of vascular surface by means 

 of which the blood is cleansed and vivified. Large lungs, 

 as a necessary corollary, lead to a large circulatory system ; 

 and that of the bat is developed in a very striking degree. 

 Finally, the position of the body, during flight, is parallel, 

 or nearly so, with the plane of the earth's surface. 

 (7o be conliiuted.) 



