December 30. 1887.] 



SCIENCE. 



321 



members of the club will please send their names and addresses to 

 Dr. F. Boas, 47 Lafayette Place, New York. 



— Mr. Montagu Kerr has left for Zanzibar to undertake a jour- 

 ney of some venture across Africa. Mr. Kerr has already done 

 good work in Africa, in the journey which he made, almost single- 

 handed, from the Cape to the Zambesi and Lake Nyassa, partly 

 through new country and among some very troublesome tribes, 

 whom he managed with great tact. In his present expedition, 

 which he undertakes entirely at his own charge, Mr. Kerr means 

 to proceed through Massai-land to the north end of Victoria Nyanza, 

 and thence to Emin Pacha's station at Wadelai. His further course 

 will be to some extent guided by Emin Pacha's advice ; but his 

 present intention is to proceed westwards to the Lake Chad region, 

 where he hopes to do some good exploring work, and then, if pos- 

 sible, go on to the Niger and descend that river. Mr. Kerr has a 

 strong letter of recommendation from the Marquis of Salisbury to 

 the British consul at Zanzibar. It is possible that when he reaches 

 Zanzibar Mr. Kerr may meet Mr. Stanley, or at least hear of the 

 results of his mission, and may thus be led somewhat to modify his 

 plans. But whatever course he may take, if he keeps his health, he 

 is pretty sure to do some good work. He has, since his return from 

 his last expedition, done every thing possible to qualify himself for 

 scientific observation, and is quite prepared to pass muster as a 

 Mohammedan in the most fanatical Moslem districts. Mr. Kerr is 

 furnished with a set of instruments by the Royal Geographical 

 Society. All who know him have confidence in his pluck and dis- 

 cretion. 



— In the October Mo7ithly Weather Review, the long drought 

 of 1887 is discussed. During the six months from May to October 

 inclusive, the rainfall has been largely deficient over the district 

 between Dakota, Michigan, Kentucky, and Kansas. Less than 

 one-half the usual amount of rainfall during these months has fallen 

 in central Ohio. Less than three-fourths of the average amount of 

 rain has fallen during these few months from Michigan, Ohio, and 

 Kentucky westward, to include Missouri and Iowa. Of special 

 interest is a compilation of excessive rainfalls in the month of Oc- 

 tober for a series of from ten to sixteen years. In a letter to the 

 Engineering News, General Greely says, " It is the intention of this 

 office to continue this discussion by months. A systematic effort 

 has been made to make the data for succeeding months more com- 

 plete and full than for October. In addition, the chief signal-officer 

 has issued instructions to the observers, calling their especial atten- 

 tion to heavy rainfalls." The Engineering News, in an editorial, 

 had emphasized the importance of measurements of heavy rain- 

 falls ; and in reply to this the chief signal-officer writes, that if the 

 engineers of the country are in earnest about this matter, and will 

 persuade Congress to appropriate twenty-five hundred or three 

 thousand dollars for the purpose of buying self-registering rain- 

 gauges, efforts will be made to spend the money economically, and 

 to distribute the gauges so as to completely cover the country. It 

 is very desirable that the plan should be carried out, as these obser- 

 vations, in connection with the gauge measurements published in the 

 reports of the chief of engineers, would be highly valuable from a 

 scientific as well as from a practical point of view, as the interval 

 between excessive rainfalls and floods and the influence of the char- 

 acter of the rainfall upon that of the flood is of eminent importance 

 for the low parts of the country and for the construction of roads, 

 canals, and other works. 



— The first number of The American Geologist has just been 

 issued. It is stated in the prospectus that the journal will be de- 

 voted to geology in its widest sense, and to allied sciences in all 

 those directions where their special investigations bear directly upon 

 the constitution and history of the globe. A journal of this char- 

 acter will be highly welcomed by all interested in the subject ; and, 

 as the amount of geological work done in North America is very 

 great, it will undoubtedly flourish, and become indispensable to 

 students of American geology. The continuous increase in the 

 number of journals devoted to special sciences is highly gratifying, 

 as it is proof of a rapid progress of science, and as it prevents the 

 scattering of investigations in one branch of science through numer- 

 ous journals. The editors are Prof. S. Calvin, T. W. Claypole, Dr. 

 Persifor Frazer, Dr. L. E. Hicks, E. O. Ulrich, Dr. A."Winchell, and 



Prof. N. H. Winchell. It is published in Minneapolis. The first 

 number contains interesting communications on the International 

 Congress of Geologists, on geological problems and observations 

 in Minnesota and Iowa, editorial comments, and a review of recent 

 literature. 



LETTERS TO THE EDITOR. 



*,* Corres/tondeiits arc requested to be as brief as possible. The writer's name is 

 in all cases required as pyoo/of good faith. _ . .„ , ^ .,^ 



T'veiity copies of the number containing his communication will be furmskea 

 free to any correspondent on request. 



The editor will be glad to publish any queries consonant with the character of 

 the journal. 



The Mechanism of the Flight of Birds. 



The subject of the interesting letter by my friend Prof. J. S^ 

 Newberry in a late number of Science is an extremely important 

 one, which has lately been discussed before the National Academy 

 of Sciences and the Linnasan Society of New York, by Professor 

 Newberry. Professor Trowbridge, and others. Much as I regret 

 my absence on those occasions, I am still more sorry to be obliged 

 to dissent without qualification from the position taken by these 

 gentlemen, which is, to my knowledge, quite untenable. Since the 

 matter has been published, I crave permission to state the facts in 

 the case, and incidentally to present the very curious history of the 

 discovery of the remarkable mechanism of flexion and extension in 

 birds' wings, involving what I would call the ' precession and re- 

 cession of the radius along the ulna.' 



First, With regard to the alleged lockingof the primaries : i. It 

 does not take place ; 2. Did it take place, flight would be impossible. 



Second, Extension of the carpo-metacarpus upon the ante- 

 brachium is automatically effected whenever the antebrachium is 

 extended upon the brachium ; and, conversely, flexion of the carpo- 

 metacarpus upon the antebrachium is automatically effected when- 

 ever the antebrachium is flexed upon the brachium. In other 

 words, the elbow and wrist of a bird work together, and neither 

 can be bent or straightened to any considerable extent without the 

 other being also bent or straightened. This motion, be it observed,, 

 in the cubito-carpal joint, is not flexion and extension in the usual 

 technical sense of those terms, but is the movement commonly 

 called, as in human anatomy, adduction and abduction. Moreover,, 

 the peculiar movement of the cubital bones (radius and ulna) which 

 produces pronation and supination (as in man and many other 

 mammals which use their fore-paws as hands) is reduced to a min- 

 imum, if not absolutely nil, in a bird's wing. It is just these 

 points : {a) substitution of adduction and abduction for flexion and 

 extension ; (B) substitution of the lengthwise sliding back and forth 

 of the radius along the ulna, or recession and procession, for that roll- 

 ing sidewise of the radius upon the ulna which is pronation and supi- 

 nation ; and (f) the reciprocal interaction of the elbow and wrist- 

 joint, — it is just these points, I aver, which are the gist of the- 

 peculiar mechanism of birds' wings, so far as the bones themselves- 

 are concerned. 



All these points are fully described, and illustrated by figures, in 

 two of my works ; namely, ' Proceedings of the American Associa- 

 tion for the Advancement of Science, for 1871 ' (vol. xx., pub. 1872,. 

 pp. 278-284); and ' Key to North American Birds ' (2d edition, 1884^ 

 pp. 106 seq.). . 



Third, The history of the case is curious, showing the quadrupled 

 discovery of the precession and recession of the radius by four inde- 

 pendent observers: {a) Bergmann (1839), (b) Wyman (1855), (c) 

 Coues (1871), id) Garrod (1875). To take these up in reverse- 

 order : — 



{d) Garrod (A.H.), ' On a Point in the Mechanism of the 

 Bird's Wing,' Proceedings of the Zoological Society, Feb. 16, 1875, 

 pp. 82-84. [The gist of the paper is the peculiar sliding motion of 

 the radius along the ulna. Garrod writes as an independent dis- 

 coverer, as no doubt he was, or he would of course have referred to 

 the previous writers.] 



(ir) CoUES (E), ' On the Mechanism of Flexion and Extension in 

 Birds' Wings," Proceedings of the American Association for the 

 Advancement of Science, xx. for 1871, pub. 1872, pp. 278-284; ab- 

 stract in American Naturalist, v. 187 1, pp. 513, 514 ; reproduced 

 in substance. Key to North American Birds, 1884, pp. 106 seq.. 

 [See text above. The writer, like Garrod, was ignorant when he 

 made the discovery that any one had preceded him.] 



