46 



SCIENCE. 



[Vol. XVII. No. 416 



cone, the base of which is directed forwards, each wing of Itself 

 forms two cones, the bases of which are directed backwards and 

 outwards, as shown at Fig. 116. In this figure the action of the 

 wing Is compared to the sculling of an oar, to which It bears con- 

 -siderable resemblance.' The one cone, viz., that with its base 

 directed outwards. Is represented &t xb d. This cone corresponds 

 to the area mapped out by the tip of the wing In the process of 

 •elevating. The second cone, viz., that with its base directed back- 

 wards, is represented at qp n. This cone corresponds to the area 

 mapped out by the i30sterlor margin of the wing in the process of 

 propelling. The two cones are produced in virtue of the wing 

 rotating on its root and along its anterior margins as it ascends 

 and descends (Fig. 80, p. 149; Fig. 83, p. 158). The present figure 

 (116) shows the double twisting action of the wing, the tip de- 

 scribing the figure of 8 indicated abcfghdijkl; the pos- 

 terior margins describing the figure of 8 indicated at p r n." 

 We readily see that the cone xb d is formed by the downward or 

 elevating stroke, the wing passing from a & to a; s and c d. It is 

 an elevating power both because of the direct lifting-power of tlie 

 wing from a b to x s, and because of the action of the two wings 

 on the wedge or cone of air formed by the line c d and its corre- 

 spondent of tlie opposite side. In this case the wing is in each of 

 its positions extended on the lines ab, xs, and c d. But I can't 

 as readily explain the cone qp n. That this transverse section of 

 the wing does not run parallel to the lines op, qr, and m n if its 

 edge be turned downward on the down-stroke and upward on the 

 up-stroke, is evident. The down-stroke is the propelling one. Let us 

 see how it produces the cone. I have added the line 1 3 to the figure 

 to represent the position of a transverse section of the wing during 

 its downward course. As we have been told that the primaries, sec- 

 ondaries, etc., roll down into this position upon the wing being ex- 

 tended, and as the wing is extended nearly at or upon the commence- 

 ment of the down-stroke, we find that the plane of this section cuts 

 the line op at an angle of about 60°, the line i^ r at an angle of 

 about 30", and only becomes parallel to mn. Then here, as else- 

 where, I have shown, we have very opposite causes producing the 

 same efiect. Now, let us see what really would be the result of 

 this. We are told that the wing works upon compressed air, that 

 "it produces a whirlwind of its own upon which it acts," etc. 

 Let qp n represent, then, the cone of compressed air. The wing 

 1 3, cutting into this cone at the angle which it does, will of ne- 

 cessity be forced backwards towards the base p r n, instead of 

 gliding along op, as it would were its posterior margins elevated 

 so that its plane lay in the direction op. The same state of 

 affairs, only reversed, would take place during the upwai'd stroke 

 ,of the wing. 



In this discussion I have considered the wing as having a flat 

 ■Stnface. That it is somewhat screw-shaped, i.e., twisted upon its 

 axis, does not altar, so far as I can see, any of the principles here 

 involved. It appears to me that during all of the discussion of 

 flight Dr. Pettlgrew has entirely failed to distinguish the difference 

 between an active and a passive organ. In the Inclination of the 

 wings he has reasoned as though the air was acting on the wings 

 instead of the opposite state of affairs, which occurs in active 

 flight, where the wings act upon the air. 



There are numerous other points in aerial, aqueous, and terres- 

 trial locomotion where I cannot help thinking that our author has 

 «rred ; but, as none of them Involve such fundamental principles 

 as have here been discussed, I will not now allude to them. 



Henkt L. Waed. 

 Tacubaya, D.F., Mex., Deo. 30, 1890. 



The American Idea of Architecture. 



The statement In a recent issue of the Record and Guide, that 

 the dominant conditions of American architecture "are not those 

 that make for the greatest beauty, or for the highest health, or 

 for charm, but for the largest return in cash," is a most alarming 

 iudication of the estimation in which architecture is held in this 

 country. Coming from so eminent a source, it carries additional 

 weight, and shows very clearly that even those who by profession 



" 1 In sculUug, strictly speaking. It Is tbe upper surface of the oar which is 

 most effective, whereas In flying it is the under." 



are nominally responsible for all that is great or good, poor or 

 indifferent, in the important art of architecture, have given up 

 hope of elevating it to the broader platform which it occupied in 

 past times; and surely, if the doctors have admitted the patient 

 incurable, it is obviously unwise for an outsider to maintain the 

 contrary. 



This utterance of the Record and Guide is an admission from 

 exalted quarters that in architecture all considerations must be 

 sunk save those of dollars and cents. It shows, what Indeed may 

 be gathered any day in a brief walk through almost any street of 

 our chief cities, that the idea of art quality, of utility, of the , 

 natural effects of the environment, and many similar causes vvhose 

 influence is to be traced in all the good architecture of previous 

 periods, are quite wanting in the art of the present day and gen- 

 eration. It is an indication of indifference to every thing but cost, ♦ 

 of measuring art values and art qualities by the price per square 

 inch, or, which is much the same thing, by the revenue per square 

 foot, — most necessary to keep in mind, but altogether improper 

 in judging of architectural merits. The point to be remembered 

 is not the falseness of this criterion, not its absurdity, but the 

 candid admission by an undisputed authority that it is the cardinal 

 principle in American architecture, and that it is useless to con- 

 tend against it. And, indeed, it might well be so; for if this idea 

 has become firmly rooted in the minds of those who are concerned 

 with architecture, who are erecting buildings as well as designing 

 them, it is impossible to look for any better results than we have 

 already obtained. 



There is not only a popular misconception that architecture is a 

 matter of cost, but also that it is concerned chiefly with the ex- 

 teriors of buOdings, and is not a science of plan, convenience, use, 

 and similar influences. It Is not the least sui-prising that a people 

 who view their architecture through the medium of price should 

 believe that the whole of it should be visible to the world at large 

 in the exterior of their structures. That the American public Is 

 prone to judge of architecture by external esthetic qualities is 

 quite evident from the recent exhibition of the Architectural 

 League in New York. This body is composed of the leading 

 architects in the city, and its work is naturally the product of the 

 best architectural culture in the country. Its annual exhibitions 

 are looked upon by that section of the public interested in the 

 serious treatment of architectural ideas as authoritative indica- 

 tions of whatever progress may have been made in American 

 architecture during each year. Certainly the personnel ot this 

 society, and the names of those who send their work to its exhi- 

 bitions, are sufficient justification for the estimation in which it is 

 held. The exhibition that has just closed cannot be viewed as at 

 all satisfactory to the public it was designed to instruct; and this, 

 not because the work showp was of an Inferior quality, not be- ' 

 cause it was lacking in firm, intelligent treatment, or was deficient 

 in ideas, but because the drawings consisted solely of exteriors 

 and picturesque effects. 



It is not in the least critical of the work shown, to remark, that, 

 in confining itself to these aspects of architecture, this important 

 body of American architects has given its formal sanction to the 

 idea that if a building looks well, all has been done that is need- 

 ful to make it good architecture. On no other grounds does It 

 appear possible to explain the predominance of exteriors in this 

 collection. It is to be admitted that the artistic treatment of 

 exteriors is one of the most important problems the architect has 

 to deal with; but it is only one, and architecture has to do with 

 many. It is not unreasonable to insist that It is quite as important 

 to cover a given area well as to erect a fagade that extends up- 

 wards into space for any desired distance. There is, however, a 

 widely extended opinion that architecture is a matter of outsldes, 

 and is not at all of what is within. The outlook for American 

 architecture is, in truth, discouraging when such a view receives 

 the ofiScial support of an eminent body of architects. 



It is not to be supposed that so advanced a journal as the 

 Record and Guide should be backward in presenting the same idea. 

 In a late issue it gave a review of the work done on the west side 

 of New York, the seat of the most active building operations in 

 the metropolis, in which, out of .sixty-four illustrations, forty-nine 

 were of exteriors, twelve bits of Interiors, and three plans. It 



