September 15, 1892] 



NATURE 



465 



the D-line into the instrument, however, I found the stellar line 

 to be distant from it towards the violet by a quantity equal to 

 the interval between the nebular lines. This gives a wave- 

 length of 580-1, which agrees closely with a bright line in Nova 

 Cygni, in the Wolf-Rayet stars, and in 7 Argiis (compare Coper- 

 nicus, ii. p. 112, and iii. pp. 205 and 206). The continuous 

 spectrum seemed to begin somewhat suddenly at 569*4, and 

 faded away about 540. 



On each night of observation the star was about 9*6 magni- 

 tude. Ralph Copeland. 



Dunecht, September 6. 



Daytime Seeing at the Lick Observatory. 



To some of the readers of Nature it may be a matter of 

 considerable surprise, as it certainly was to the writer, to find 

 the marked superiority which a small telescope sometimes offers 

 over a large one for the observation of solar prominences. 



On numerous occasions during the last year, while adjusting 

 the large star spectroscope of this observatory to the 36- 

 inch refractor, I have improved the opportunity to examine the 

 limb of the sun with a Rowland grating. At no time, however, 

 has it been possible to get any definition in prominence. With 

 the 6-inch equatorial, on the contrary, one gets very fair 

 definition, even in the middle of the day ; while in the early 

 morning, from six to eight o'clock, the seeing is, as a rule, 

 superb. Thinking these differences might possibly vanish if the 

 larger glass were used earlier in the morning, I have recently 

 made a systematic comparison of the three equatorials, viz., the 

 6-inch, the 12-inch, and the 36-inch. For this purpose a 

 small grating spectroscope (kindly loaned .by the Chabot 

 Observatory) was used with an adapter Mhich fitted all 

 three telescopes, so that the whole comparison could be made 

 in a few minutes. The third and fourth orders of a 14438-line 

 grating were employed. 



The result of a half-dozen mornings' observations was that ! 

 no detail whatever could be made out with the 36-inch, how- I 

 ever much care one might use in the adjustment of his instru- ' 

 ment. One could form a rough estimate of the height and 

 general outline of the prominence, but nothing more. 



On the 12-inch the general features were considerably more 

 distinct, but the fine delicate tracings of the various parts of the 

 prominence could be seen only with the 6-inch. The capping 

 down of the 36-inch and the 12-inch failed utterly, as might 

 have been expected, to improve the definition on any occasion. 



The large image of the sun given by the 36-inch (six inches 

 in diameter), combined with the poor seeing during the daytime, 

 makes the instrument act, for suiispot observation, very much 

 like an integrating spectroscope. The lines affected by absorp- 

 tion, in spots of any considerable size, can be picked out readily, 

 but one finds it quite impossible to compare the absorption of 

 the nucleus with that of the penumbra. These three telescopes 

 each give images of nearly the same brightness, and one does 

 not find much, if any, difference in the amount of dispersed light 

 in the field. 



During the dry season, the sides of the canons surrounding 

 this observatory become intensely hot, and highly heated cur- 

 rents of air are continually rising from them. So that, proba- 

 bly, the conditions which make the order of efficiency of these 

 telescopes in the daytime just the reverse of what it is at night, 

 are purely local. Henry Ckew. 



Lick Observatory, August 19. 



Ridgway on the Humming-birds. 

 Mr. Robert Ridgway, curator of the bird department of 

 the U. S. National Museum, has just published (in separate 

 form), in the report of that institution for 1890, his monograph of 

 the Trochili. Coming from such an authority and essaying to 

 •deal with such an interesting group, this work will undoubtedly 

 command the attention of ornithologists, and be studied with 

 the care it no doubt merits. It makes its appearance in octavo 

 form, of some 130 pages, being illustrated by 46 full-page plates, 

 and has besides a number of cuts in the text. The plates give 

 us many species of humming-birds and their nests ; they being 

 all of the "electro-process" variety, and chiefly copied from 

 Gould's princely work upon the Trochili. As is usually the case, 

 most of the figures given have suffered by the method of repro- I 

 duction employed, and not being coloured, they offer us, at the j 



NO. I 194, VOL. 46] 



best, with but a poor idea of the "living gems" they are sup 

 posed to portray. With more or less thoroughness Mr. Ridgway 

 has touched upon the early history and the literature of his 

 subject ; upon the geographical distributionof the various species; 

 upon their number, which he makes out to be about 500 ; upon 

 their natural history in general (treated in various brief sections) ; 

 and there are descriptions of their external characters and a short 

 note upon a few of their internal ones. It is with the statements 

 made in the latter that I chiefly propose to deal in the present 

 connection, and, aware as I am of our author's knowledge of 

 the literature of what we may call the natural history and classi- 

 fication of the humming-birds, as contra-distinguished from 

 their morphology and affinities, I must confess my surprise at 

 his ignorance of the latter part of his subject. Mr. Ridgway 

 remarks (p. 290) that " the humming-birds possess nothing 

 absolutely peculiar, although certain features, shared by other 

 groups of birds, notably the swifts {Micro pjdidx), are developed 

 to an extreme degree ; as, for example, the very high keel to 

 the sternum and consequent excessive development of the 

 pectoral muscles, the short arm wing (humerus) and extremely 

 long handwing (manus), and minute feet with relatively large, 

 strongly curved, and sharp claws. The humming birds and 

 swifts further agree in numerous anatomical characters, and 

 there can be no doubt that they are more closely related to 

 each other than are either to any other group of birds. In fact, 

 except in the shape of the bill and structure of the bones of the 

 face, the humming-birds and swifts present no definite differ- 

 ences of osteological structure." As the present writer has 

 probably published double the number of accurate figures 

 illustrating the entire anatomy of a great many species of hum- 

 ming-birds as compared with any ether worker ; and, further, 

 has published correct accounts of the same to the extent 

 exceeding that of any three living avian-morphologists, and 

 those figures and descriptions having been very extensively 

 accepted as correct, perhaps our author will consider me com- 

 petent to criticize the statement which I have just quoted from 

 his work. Notwithstanding the extensive and painstaking 

 labour I have given to such matters, I reckon it but as little 

 when compared with the opinions given us by Huxley and 

 Kitchen Parker in the same premises. 



As long ago as 1867 (P. Z. S., p. 456), Huxley expressed the 

 view that " in their cranial characters the swifts are far more 

 closely allied with the swallows than with any of the Des- 

 mognathous birds, the swift presenting but a very slight 

 modification of the true Passerine type exhibited by the 

 swallow ; " and Parker has said in The Zoologist for March, 1889 

 (p. 2), "I agree with my friend, Dr. Shufeldt, that the 

 'swallow and the swift are near akin.' My opinion is not 

 the simple judgment it Was forty years ago. I have observed a 

 good many things since then in the structure of birds of all 

 sorts." Both of these high opinions 1 can confirm, and in sup- 

 port of them, and as contradicting every statement almost that 

 my good friend and ornithologist, Mr. Ridgway, has made in 

 his work touching the structure of swifts and humming-birds, I 

 would invite his attention to many comparative figures and 

 accounts published by me in the Proceedings of the Zoologi- 

 cal Society of London at various times, and also to an extensive 

 paper of mine which appeared in the Journal of the Linnean 

 Society of London, in 1888 or 1889, having been read at the 

 Society by W. K. Parker, F.R.S., who accepted, in the main, 

 what 1 had stated in it. Therein I anatomically compare the 

 entire structure of every species of United States swallow with the 

 corresponding structures in a great many swifts and a great many 

 humming birds, and I would invite Mr. Ridgway's attention to 

 the synoptical comparisons given on pages 376-378, especially as 

 off-setting his statement, as quoted, that "in fact, except in the 

 shape of the bill and structure of the bones of the face, the hum- 

 ming-birds and swifts present no definite differences of osteo- 

 logical structure." And, unless as a true systemist and believer 

 in colours and nieasurernents rather than in structural characters 

 as determining the real affinities of vertebrate forms, I would 

 finally invite his consideration of my comparative figures and 

 description of the humerus of a swallow, a swift, and a humming- 

 bird given in the Proc. Zool. Soc, Lond., for 1887 (pp. 501- 

 503), and then ask his candid opinion upon the question whether 

 the humerus of a swift is morphologically more like that of a 

 humming bird than it is like that of a swallow, and the humerus 

 is one of the bones that has been so frequently dragged into the 

 discussion to prove cypselo-trochiline affinities. 



Washington, D.C., July 24. R. W. Shufeldt. 



