Waterbury evening Democrat., 1894-02-15
AS THE BIRDS SOAR.
THEY POINT TO NOVEL IDEAS OF ME-
 CHEMICAL IMPORTANCE.


 CHEMICAL IMPORTANCE.
 Bodies Weighing Ten Pounds Float In the
 Air For Hours Without Apparent Effort.
 sonian Institution.
 It has long been observed that certain species of birds maintain themselves in- definitely ill the air by soaring, without any Tapping of the wing or any motion other than slight rocking of the body, and thls although the body in question is many hundred times denser than the air in which it seems to float with an undulating movement as on the waves of an invisible stream.
 No satisfactory mechanical explana- tion of this anomaly has been given, and none would be offered in this con- nection by the writer were he not satis- fled that it involves much more than an ornithological problem, and that it points to novel conclusions of mechan- ical and utilitarian importance. They are paradoxical at first sight, since they imply that under certain specified con- ditions very heavy bodies entirely de- tached from the earth, immersed in and free to move in the air, can be sustained there indefinitely without any expendi- ture of energy from within.
 These bodies may be entirely of me- chanical construction, but for the pres ent we will continue to consider the character of the invisible support of the soaring bird and to study its motions, though only as a pregnant instance of fered by nature, to show that a rational solution of the mechanical problem is possible.
 It is frequently suggested by those who know these facts only from books that there must be some quivering of the wings so rapid as to escape obser- vation. Those who do know them from observation are aware that it is abso- lutely certain that nothing of the kind takes place, and that the birds sustain themselves on pinions which are quite rigid and motionless, except for a rock ing or balancing movement, involving little energy.
 To the writer, who has himself been attracted from his earliest years to the mystery which has surrounded this ac- tion of the soaring bird, it has been d subject of continual surprise that it has attracted so little attention from phy- sicists. That nearly inert bodies, weighing from five to ten and even more pounds, and many hundred times denser than the air, should be visibly suspended in it above our heads, some f,O1 lt n falling-this, it might seem, is, without misuse of language, to be called phys ical miracle, and yet the fact that those whose province it is to investigate nature have hitherto seldom thought it deserving attention is perhaps the greater wonder.
 The writer will not attempt any gen eral description of his own observations, but as an illustration of what can sOme- times be seen will give a single one, tc whose eXactneSs he can personally wit ness. The common turkey buzzard (Cathartes aura) is so plentiful around the environs of Washington that there is rarely a time when some of them may not be seen in the sky, gliding in curves over some attractive point or-more
 
 on rigid wings, if there be moderate wind. On tho only occasion when the motion of one near at hand could be studied in a very high wind the author was crossing the long aqueduct bridge over the Potomac in an usually violent November gale, the velocity of the wind being probably over 35 miles an hour. About one-third of the distance from the right bank of the river, and immo- diately over the right parapet of the bridge at height of not over 20 yards, was one of these buzzards, which, for some object which was not evident, chose to keep over this spot, where the gale, undisturbed by any surface irreg ularities, swept directly up the river with unchecked violence. In this aerial torrent, and apparently indifferent to it, the bird hung, gliding in the usual m tanner of its species, round and round, i'll small oval curve, whose major axis which seemed toward the winG-was not longer than twice its height from the water. The bird was therefore at all times in close view. He swung around repeatedly, rising and falling slightly in its course, while keeping, as a whole, on one level and over the same place, moving with slight swaying, both in front and lateral direction, but in such an effortless way as suggested lazy yielding of itself to the rocking of some invisible wave.
 It may be asserted that there was not only no flap of the wing, but not the quiver of a wing feather visible to the closest scrutiny during the considerable time the bird was under observation, and during which the gale continued.
 A record of this time was not kept, but it at any rate lasted until the writer chilled by the cold blast, gave up watching and moved away, leaving the bird still floating about at the same height in the torrent of air, in nearly the same circle and with the same as- pect of indolent repose.
 If the wind is such a body as it is commonly supposed to be, it is abso- lutely impossible that the sustentation could have taken place in horizontal current any more than in calm, and yet that the ability to soar is in some way connected with the presence of the wind became to the writer as certain as any fact of observation could be, and at first the difficulty of reconciling such facts-to him undoubted-with accept ed laws of motion seemed quite insu- perable. e.-Professor Langley.