;i8 



NATURE 



[August 6, 1896 



The primary feathers are each xuidely separated, thus giving a 

 superposed aeroplane, at the wing extremities — 



/-- 



the body, say 20 lb., suspended between and below them. Each 

 primary feather, which naturally is bent thus — 



is strongly bent up, by a force equal to 8 oz., thus — 



The sustaining is at the extremities, mainly. When going round 

 •with the breeze, the speed obviously increases, and the kite-like 

 lift takes place when the bird turns and meets the same, the lift 

 being visible, if near, and the speed also obviously slowed down. 



But the drift of the rising spiral is to leeward. Varying 

 momentti}!! (of bird) in the resisting medium, must be noted; a 

 stuffed albatross, or aeroplane, hung in a draught, will not solve 

 the rising riddle. 



The wing-plane for the moment is always part of a cone, outer 

 wing highest. 



When pelican travel for great distances in a straight line, their 

 flight is at times peculiar, and they fly following each other, 

 each bird alternating flaps or sails, thus — 



the line of birds a series of waves. Our large hornbills, Biueros 

 bicornis, behave in the same way. 



I believe that when we look up and see a crowd of very 

 minute specks some 5000 to 8000 feet above us (binoculars 

 often needed), we see birds which have gone up there for cool- 

 ness, and to go to sleep — to doze, at any rate. There is an entire 

 absence of the mental and physical alertness and agility, which 

 would be constantly needed if they depended on inequalities of 

 wind pressure, and equally sudden, and invisible, up gusts, to 

 save themselves from falling. 



Herr Lilienthal is probably on the right trail. I see he 

 desires to turn and meet the breeze ; but in this movement, I 

 fancy the upper central aeroplane — so high above the centre of 

 gravity — will turn him over in a strong wind. In the bird's case 

 (when turning) there is very obviously strong centripetal counter 

 pressure, and great speed, quite sixty miles an hour I should 

 suppose, at end of the leeward lap. 



I notice that " W. J. .S. L." (second paragraph, p. 301, January 

 30) assumes that the speed at times would be slower than the 

 wind. This could only be when stopping. In the bird's case, 

 the lifting is mainly done when it turns and meets the wind, 

 and speed is slowed down, and the overturning is prevented, 

 when the wings are thus, ~ - — ' < <(« to the wind, by the 

 great /a/^-a/ expanse. There is none of this latter, in the centrally 

 superposed plane machine ; the bird's great lateral steadiness 

 is structurally absent. 



Soaring machines may be of two types : A, those containing 

 their own power; and B, those deriving it from the surroundings 

 only. There is no screw in the stern of the " Bov Tokla," as 

 he wheels round and round close over me, as I sit hidden in a 

 tuft of grass on the wide plain. Rising to windward, he circles 

 over me at 200 feet or so, and with binoculars, or even without, 

 I can see each feather, and hear the loud noise they make ; there 

 is never a move, e.xcept a little in the tail, yet lap by lap the 

 bird steadily rises, and as steadily, if slowly, gets a drift to 

 leeward. 



NO. 1397, VOL. 54] 



I do not suppose the bird can soar without expenditure of 

 energy ; all I desire to point out is, that upward air currents do 

 not lift and sustain it, also that the Ufting is seen to be applied 

 to the primary wing feathers almost entirely, and in a way 

 which shows the lift is due to lateral translation. Tie a primary 

 at the end of a long light stick, and on whirling it the effect 

 is obvious. S. E. Peai,. 



Sibsagar, Asam, June 21. 



The Position of Science at Oxford. 



It is notoriously difficult to express one's whole meaning in a 

 condensed article. In so far as the article on the position of 

 science at Oxford referred to the teaching of science at public 

 schools, I see from Mr. C. I. Gardiner's letter that I have failed 

 to express my meaning, and I must hasten to remove the im- 

 pression that I intended to cast any repro.ach on the science 

 masters of our public schools. I find it, indeed, difficult to 

 understand how any one could have mistaken my meaning as 

 much as Mr. Gardiner has done, seeing that I wrote that in 

 every public school there are one or more science masters of tried 

 capacity ; a statement, I submit, which is entirely at variance 

 with Mr. Gardiner's interpretation of my remarks. He makes 

 me say that there is an absence of efficient teachers in scientific 

 subjects ; a statement which I never made, and could not make, 

 for it would be manifestly untrue. I must admit, however, that 

 a single sentence, "taken on the whole the science teaching at 

 our public schools is bad," was unfortunate : I should have said 

 that the value attached to science teaching at our public schools 

 is altogether insufficient. Let me assure Mr. Gardiner that the 

 last thing in the world that I should wish is that anything should 

 be said or done to depreciate the attainments or the authority ol 

 science masters. Perhaps I may be allowed to explain. The 

 efficiency of a machine depends firstly upon its excellence, 

 secondly on the conditions under which it works. I do not 

 dispute the excellence of science masters, but, speaking generally, 

 I deplore the conditions under which they work in public 

 schools. I stated that in pubhc schools the inducements to 

 learning science are very few (not nil, as Mr. 

 CJardiner misquotes me); secondly, that it is openly 

 discouraged ; thirdly, that boys are apt to neglect 

 studies which may safely be neglected. I adhere to 

 each and all of these propositions. Boys, /ace Mr. 

 Gardiner, are as much impelled by emulation as by 

 interest and fear (heaven forbid that fear uf the cane should ever be 

 associated with scientific teaching). Mr. Latter, in his valuable 

 letter, throws the weight of his experience in favour of my state- 

 ment : " A promising boy cannot make up by his science for de- 

 ficiency in classics or mathematics . . . whereas the acute classic, 

 however obtuse in science, is in no way hindered on his path to 

 sixth form." No more need be said : the great inducement of emu- 

 lation is wanting. If a boy neglects classics and mathematics he 

 fails to rise in the school, is superannuated and sent away. If 

 he neglects science, whilst working respectably at classics, he 

 may incur formal reproof, he scarcely incurs reproach ; at any 

 rate he is in no danger of superannuation. Is it not safe, then, 

 to neglect science ? How Mr. Gardiner could have construed 

 a harmless sentence into an attack on science teachers, I am at 

 a loss to conceive. His conclusion is certainly not contained 

 in the premisses, and I may be allowed to remind him that 

 jumping to conclusions is hardly a scientific proceeding. As to 

 the discouragement of science being no longer in existence, I can 

 only say that Mr. Gardiner's experience is happier than mine. I 

 trust his experience will soon become universal. 



Boys do come to Oxford and to Cambridge destitute of scientific 

 ideas. I have ample experience in Oxford, and my Cambridge 

 friends make the same complaint. There are, of course, some 

 few who have made science a speciality, and are well grounded, 

 but the majority are absolutely ignorant of the alphabet of 

 science. It is a well-known fact, and may be proved in the 

 following way. Let it be proposed that a paper in rudimentary 

 physics be compulsory in the " Little Go" at Cambridge, .and in 

 ".Smalls" at Oxford. The proposal will be rejected by both 

 Universities, because, it will be alleged, this minimal knowledge 

 of science would be an insuperable barrier to the classical 

 scholar. Moreover, it is the universal experience of those who 

 are engaged in science teaching in the two Universities, that 

 much of their energy is wasted in teaching the alphabet of science 

 to those who propose to take honours in that subject. That 

 alphabet might have been learned at school. I make no 



