4 88 



NATURE 



I i BRUARY 20, 1919 



iperated in developing a new type oi rectifying 

 chin< B) Jul) , [918, the pro- 

 tion ni helium in moderate quantities was ac- 

 complished, and From thai time onward the possi- 

 bility of securing large supplies of helium was 

 assured. 



Concurrently, all practical details oi the pro- 

 duction ni helium-borne airships and of the navi- 

 gation of this type oi (rail were d< veloped by the 

 airship production section ol the Navy. At the 

 same time, under the direction ol Prof. McLennan, 

 plans were prepared and steps taken to en-r- 

 and equip a station lor purifying the helium which 

 might become contaminated in service. Experi- 

 mental investigations were also initiated with the 

 object ol developing the possible technical and 

 scientific uses of helium. In particular, balanci 

 and spectroscopic methods for testing the puritj 

 of the gas were worked out, studies on the relative 

 permeability of balloon fabrics to hydrogen and 

 helium were commenced, and experiments were 

 begun to exploit the use of helium in gas-filled 

 incandescent lamps, gas-filled arc lamps, and 

 thermionic valves. The equipment provided for 

 the purification of contaminated helium in large 

 quantities supplied the major portion of the ap- 

 paratus required to liquefy helium, and arrange- 

 ments were therefore made to produce this gas in 

 a liquid form. 



The advances already made by the time the 

 Armistice commenced warrants the opinion that at 

 the end of another year large supplies of helium 

 would have been produced within the Empire at a 

 low cost, helium-filled aircraft would have been in 

 service, and great progress would have been made 

 in exploiting the technical and scientific uses of 

 this gas. 



Before the war a proposal to utilise helium as a 

 filling for airships would have been viewed, even 

 by men of science, as akin to a proposal at tin- 

 present time to pave the Strand with diamonds. 

 Thanks, however, to the enterprise, enthusiasm, 

 and initiative of the Navy, backed by imagination, 

 a suggestion — at one time considered to be chi- 

 merical — has to-day become a realisation. 



BIRDS AXD THE IV A R. 

 \^7ITHIN the limits of a short article it is not 

 * * possible to do justice to our feathered 

 friends. The services rendered by homing- 

 pigeons to the Army, Navy, and Air Forces have 

 been invaluable, and numerous stories of their 

 gallantry and devotion, under fire and even when 

 wounded, have alread) appeared in the daily 

 newspapers. Canaries, long- recognised as the 

 miners' friends in detecting the presence of 

 poisonous underground gases, have played their 

 pari in the war by being used in the trenches and 

 dug-outs when the presence of German poison- 

 gas was suspected. It is not so generally known 

 thai parrots, in the earliei days of the war, were 

 employed on the Eiffel Towei to give warning 

 the approach of enemy aircraft. Sea-gulls, on 

 1 than one occasion, bi tra j ei 1 th< present - 

 1573, VOL. I02] 



ol submarines and mines and thus prevented 

 disaster to our sailors. 



On the actual battlefield the behaviour of birds 

 has been remarkable. Unperturbed b) the terrible 

 rackel and the bursting of gas-shell's, a nightin- 

 gale trilled its sweetest, a soaring skylark poured 

 out its song, a blackbird sang- the more merrily 

 the heavier the bombardment, swallows twittered 

 around, and nested in, tin- haltered ruins oi \ 

 Cathedral even when it was under fire; a "minnie- 

 shell, " which burst in the middle of a covey of 

 partridges, did not alarm them and they went 

 on feeding unconcernedly a few seconds later. 

 In fact, it ma) lie said that the birds, wherever 

 they could eke out an existence, seemed oblivious 

 to the life-and-death struggle going on all round 

 them. 



At home the consensus of opinion of trust- 

 worthy observers shows that birds were at first 

 much upset by air raids. As these, howi 

 became more frequent, their fears diminished. 

 There can be little doubt that birds are adaptable 

 creatures, and soon become accustomed to loud 

 noises. As an example of this, it may be stated 

 that when the bells of St. Paul's were rung, alter 

 a protracted silence, to celebrate "Armistice 

 Day," the City pigeons, long unaccustomed to 

 such sounds, appeared to be seriously alarmed, 

 though in days of peace they paid no attention 

 to the daily chimes. 



The restrictions on food, imposed on all loyal 

 citizens, made it an offence to feed birds and 

 prosecutions ensued. A sportsman was fined for 

 feeding pheasants on grain, and more than one 

 kind-hearted person paid the penalty for feeding 

 birds on scraps. Cage birds were difficult to 

 keep, and never were parrots more freely offered 

 on loan to the Zoological Gardens. 



The strenuous orders issued to farmers to 

 plough up the maximum amount of their land was 

 followed by a misguided outcry against all birds. 

 Thanks to the efforts of the Royal Society for 

 the Protection of Birds, and a few reasonable 

 ornithologists, the agriculturists were persuaded 

 that, after all, the majority of birds do more good 

 than harm. There are, however, several enact- 

 ments made against birds (such as the extension 

 of the period for burning heather, the prolongation 

 of the shooting season for grouse and blackgame, 

 and the "Destruction of Pheasants Order") 

 which, it is to be hoped, will shortly be modified 

 or repealed. 



Reports are not yel to hand as to how birds 

 fared in enemy countries; probably they were no 

 better off than they were in Great Britain. Such 

 items as have evaded the strict German censor- 

 ship, regarding the shortage of food, tell us that 

 rooks were sold and eagerly bought as articles 

 of diet. It is amusing to note that a corre- 

 spondence, carried on in one of our leading daily 

 newspapers, as to the edibilit) of gannets, gulls, 

 etc., was ingeniously interpreted by the German 

 newspaper-men as showing- that England was 

 starving owing to the invincibility of the l"-boats. 

 Migration does not appear to have bi 



