April 28, 1910] 



NA TURE 



263 



these birds are to be seen on the lake at seasons when 



le majority of their kindred are in far distant lands. 



hese observations and their results have been published 



the Bulletin de la Societe Vandoise des Sci. Xat. for 



)05 and 1910. The gulls are most numerous from the 



id of July to the middle of October — during which period 



leir numbers may reach as man%- as 3600 — but the great 



ulk disappears during the breeding-season, and again in 



inter. For their breeding resorts in the north the birds 



tke their departure towards the end of March, although 



few hundreds remain on the Haut Lac throughout the 



jason. Of these stay-at-home individuals only a small 



ercentage nest on the lake, and it seems probable that 



le great majority are aged birds the breeding-days of 



^hich are over. On the other hand, a certain number of 



ligrating gulls reappear on the lake at the beginning of 



uly, several weeks before their fellows. Several explana- 



ons of this have been given, but it seems, on the whole, 



lost probable that these early arrivals are birds which 



ave completed their parental duties in the north at an 



nusually early date. It is well known that dark barrings 



n the tail are a sign of immaturity in this species, which 



enerally disappear when the birds are about eighteen 



lonths old ; on the other hand, the dark cap on the head 



not assumed until the third year, while the birds do not 



ay until they are twenty-three months old. A certain 



umber of birds are. however, met with in their second 



unimer with the tail barred and the head dark, and these 



oust probably be regarded as precocious individuals. 



•"inally, the author has succeeded in demonstrating that 



he black-headed gull is not a diver. 



The Land .Agents' Society some time ago commissioned 

 vfr. Walter E. Collinge to institute an inquiry into the 

 eeding-habits of rooks, the results of which have been 

 jublished in pamphlet form by Messrs. Laughton and Co., 

 td., Wellington Street, Strand. Observations made on 

 nore than 800 specimens from various parts of England 

 indicate that (i) 67-.T per cent, of the food of these birds 

 consists of grain, this, by the inclusion of roots and fruits, 

 >eing raised to 71 per cent. ; (2) the animal-food is 29 per 

 -enT.. of which fully one-third is to be reckoned against 

 he utility of the rook : (3) a grain-diet is certainly pre- 

 ferred ; (4) the rook is not a particularly beneficial bird to 

 the agriculturist, although its utility might be increased 

 f its numbers were diminished. 



In connection with the above, reference may be made to 

 1 paper by Dr. J. E. H. Kelso in the April number of 

 the Zoologist, where it is shown that, in addition to doing 

 ronsiderable damage to fruit, the starling is nowadays an 

 ?nemv to the farmer bv devouring considerable Quantities 

 jf wheat, such grain being presumably devoured for its 

 iwn sake, and not on account of containing grubs. This 

 ».'heat-eating propensity' is considered to be a modern 

 levelopment. 



In the same issup Mr. E. J. Stubbs makes out a stronff 

 ?laim. not onlv that the white egret {Ardea garzetta) 

 should be added to the British list, but likewise that in 

 he Middle .Ages it was a common species in our islands. 

 From various old works the author ouotes passages 

 ndicating that a small white heron-like bird, without a 

 nesr, was commonlv out on the table at state banquets 

 n the north of England, where it was taken in the 

 leighbouring marshes, and that this bird could have been 

 lothing else than the egret, by which name it is indeed 

 nentioned. The idea that the lapwing could have been 

 ntcnded is shown to be altogether untenable, and, indeed, 

 he author adduces evidence to show that the present 

 ibundance of the latter bird is a modern feature. 



LAXGLEY'S COXTRIBUTIOXS TO 

 AERONAUTICS.' 

 T^HE award of the Langley medal to the Brothers Wilbur 

 and Orville Wright emphasises the fact that we are 

 iving in an age of great achievements. The twentieth 

 ;entury had hardly dawned when the world was startled 

 )y the discoverv of radium, which has opened up nn 

 mtirely new field to science, and has led us to modify 



1 Address deliverer) by D'. Alexander (Ua^am Bell at th^ pres-nt»fion of 

 he L'nglev medal of the Smithsonian Institution to the Wright Brothers 

 n February to. 



NO. 21 13, VOL. 83] 



profoundly our conceptions regarding the constitution of 

 matter. Another new field has been revealed to us 

 through the development of wireless telegraphy and 

 telephony, and we now utilise the vibrations of the aetherial 

 medium of space for the transmission of thought. 



Then, again, we may note the most revolutionary 

 changes going on before our eyes relating to methods of 

 transportation. The appearance of the hydroplane-boat 

 probably foreshadows a revolution in marine architecture 

 and propulsion. On land we see motor-cycles, automobiles, 

 and electric cars displacing the horse. Petroleum and 

 electricity have become powerful rivals of steam, and we 

 seem to be on the eve of a revolution in our methods of 

 railroad transportation through the application of the 

 gyroscope to a mono-rail system ; and now aerial transport 

 has come, dispensing with rails and roads altogether. The 

 air itself has become a highway, and dirigible balloons and 

 flying machines are now realities. 



How well the predictions of Langley have been fulfilled. 

 We now recognise that he was right when he said, a few 

 years ago (1897), that : — " The world, indeed, will be 

 supine if it do not realise that a new possibility has come 

 to it, and that the great universal highway overhead is 

 now soon to be opened." 



It has been opened : and who can foretell the con- 

 sequences to man? One thing is certain, that the physical 

 obstacles to travel have been overcome, and that there is- 

 no place on the surface of the globe that is inaccessible to 

 civilised man through the air. Does this not point to the 

 spread of civilisation all over the world, and the bringing 

 of light to the dark continents of the earth? 



The Pioneers of Aerial Flight. 



Who are responsible for the great developments in aero- 

 dromics of the last few years? Not simply the men of 

 the present, but also the men of the past. 



To one man especially is honour due, our own Dr. S. P. 

 Langley, late secretary of the Smithsonian Institution. 

 When we trace backwards the course of history we come 

 unfailingly to him as the great pioneer of aerial flight. 

 We have honoured his name by the establishment of the 

 Langley medal ; and it may not be out of place on this,, 

 the first occasion of the presentation of the medal, to say. 

 a few words concerning Langley 's work. 



Langley' s Work. 



Langley devoted his attention to aerodromics at a time 

 when the idea of a flying machine was a subject for 

 ridicule and scorn. It was as much as a man's reputation 

 was worth to be known to be at work upon the subject. 

 He bravely faced the issue, and gave to the world his 

 celebrated memoir entitled " Experiments in Aero- 

 dynamics." In this work he laid the foundations for a 

 science and art of aerodromics, and raised the whole subject 

 of aerial flight to a scientific plane. 



The knowledge that this eminent man of science believed, 

 in the practicability of human flight gave a great stimulus- 

 to the activities of others, and started the modern move- 

 ment in favour of aviation that is such a marked feature, 

 of to-day. 



Everyone now recognises the influence exerted by Langley 

 on the development of this art. The Wright Brothers, too,, 

 have laid their tribute at his feet. 



" The knowledge," they say, " that the head of the- 

 most prominent scientific institution of America believed 

 in the possibility of human flight was one of the influences 

 that led us to undertake the preliminary investigations that 

 preceded our active work. He recommended to us the 

 books which enabled us to form sane ideas at the outset. 

 It was a helping hand at a critical time, and we shall 

 always be grateful." 



Contributions to the Science of .ierodromics. 



Langley's experiments in aerodynamics gave to physicists,- 

 perhaps for the first time, firm ground on which to stand 

 as to the long-disputed questions of air resistances and 

 reactions. Chanute says : — 



(a) They established a more trustworthy coefficient for 

 rectangular pressures than that of Smeaton. 



(fc) They proved that upon inclined planes the air. 

 pressures were real'y normal to the surface. 



