CONQUEST OF THE AIR.

Dominion, Volume 1, Issue 304, 17 September 1908, Page 4

CONQUEST OF THE AIR.

:—* FACTORS IN THE PROBLEM. ZEPPELIN AND HIS AIRSHIPS. (FROM AN ENGINEERING COItItESrONIJENT.) London, August 7. "Deutschland, Dcutschland, über alles, , ' > uang the German peasants as Zeppelin's aerostat sailed over their heads this week. At least so the London journals tell us. In like caso the Londoner would probably have unrig: "Oh, what a sensation; a honeymoon in tho air I" or some similar music-hall ditty, lint great enthusiasm was invoked, we are informed, and the spectators seemed intoxicated with joy. They probably thought they wore watching an .inexpensive but emphatio answer to Britain's Dreadnoughts and lu. floraitables. \

What tjiey actually saw, however, was an airsbi[i with a displacement superior to the majority of tho ocean liners visiting New Zealand, carrying a dozen passengers and a sufficiency of fuel—if all went well—for a run of five or six hundred utiles. Jiut as readers of The Dominion probably know Zeppelin's aerostat had to alight after it little under twelve hours' run. She was in trouble with her motors, we are told ( but seeing that she was unable'to resume her voyage until some cylinders of gas arrived by express train it is probable that something else was amiss. Sm was -reinflated successfully enoughj but a storm arose; she began to drag her anchors about the country, and finally she caugh't fire and was reduced to an aluminium matte. It was explained at first that silo had exploded through tho ignition of benzine vapour- from. her motors, then that she had been struck by lightning. Afterwards it wiis'stated that the motors had been stopped some'time before, and wore quite cold. Vulnerable and Unvrieldy. Whatever may., be the, actual truth it yet ' remains a fact .that like all other, "lighter than .air" machines-this airship is very vulnerable, very unwieldy, and .very far .from being, past the experimental stage. Moreover, it is difficult to see how she,-and her type, will ever be able to; pass-that stage. Hydrogen—the medium employed in this case —is the lightest. gas known. ■it must ~ be'admitted that, as the White: King would i say, _ "Nothing is lighter than, hydrogen,'.',,, and if a practically perfect vacuum could be 1 maintained in the body of the balloon.-, tne • ascensional power could be increased.; Mech- .: anical conditions, however,, stand in the.'way of this, .and for tho present hydrogen' must be considered to yield : the/maximum result : in this connection. Increased lighting power can thus only be, gained by an increase of -. displacement. The aerostat under consideration, the'Patrie, ■ which came to an untimely . end last year, and even ■ the Nulli Secundusy which is only a third of the size of the others,, have, shown themselves sufficiently ; 'unmanageable when near the ground, and an increase of'displacement'must bo accom-: pauied by an'increase of unwieldiness. : v

-. But it may be argued that the mechanical , a engineers of the day are greatly improving:. - motors in tho direction of increasing ■ the ; . 0 ratio of power to weight, and tliaa further - saving of this nature would enable the airsi ship either. to carry more men, moro ex--0 plosives, or moro fuel. Data is not yet, t extant concerning Zeppelin IV; but, taking e a lino through others, the motors weigh ■ . about'9oolb. out of a . total of 13,0001b., so - that a saving of weight of even 50 per cent. 1- in tho motors could only give a range of b action increased by, a hundred' miles or so, - or enable threo . more men to be carried. ■' 3 So far, then, there is little reason; to • fear . tho dirigiblo balloon ,as a transport. 1 The Limit of Efficiency. ? But it may bo objected; that'not only will" 1 tho weightl of the motor bo,decreased pro.', 3 rata, "vrill be mado more' 3 economical." Now, there is a 'limit to the thermal 'efficiency of heat engines; as' : aiiy ': i' technical scholar ! will tell us, and it'-'is not i very far away. The very lightness of the ' 1 : > motor'sets up troubles'of a new "kind, and ; tho cooling ,of the cylinders, for exara'plo, v > becomes a matter, of-great difficulty.' , Thus tho aerostat can-hardly achieve suc--1 cess in landing, soldiers in an enemy's' coun- ) try, and. other uses must bo found for her!1: Tho first suitable'duty that suggests itself > to the magazine writers—who are mainly ' 1 responsible for tho bibliography of-the sub- ; joct—is the dropping of explosives within the ; desired area. There is 110 need to consider ; tho arguments raging among experts as to : , tho comparative' destructive powers of con-' ; fined and unconfined explosives. It may be >. assumed that tho most ordinary ' looking I brown paper parcel of dynamite,' if suitably ■ disposed, might-very considerably modify the 1 martial ardour- of a nation; also that it is 1 inconvenifnt for a goneral-officer, even in 1 the British Army, to have his dispositions , overlooked at all times by the enemy. There 1' is a possibility, . also, that a return may be mado to tho "stink-pots" of tho Elizabethanera, more. recently employed in China. A' suitable mixture of, say, sulphuric, and ar-. senious acids, with ' the proper amount of , zinc, would cause much annoyance to the .. .town upon which it fell. So that, if tho ' . aerostat can be induced to get lip in tile air and travel in tho direction for some hundreds of miles—as seems to bo the: case it behoves us to seek' the best means of .putting her.out of action. Rifles or quick-firing guns are out of tho question;-tho target is moving far too.,rap. idly, and the final destination, of stray projectiles would bo a matter of more than pass- ' mg interest. Moreover, a small bore bullet • would do but littlo harm. Neglecting the tremendously powerful electric waves which quito apart from electrical questions, would fail to eyplodo the non-explosive 'gas in the balloon envelope—there only remains attack by another airship, and it is here that tho probable solution of tho problem will ha found. Battles in the Air. An aeroplane depeiids for its ascensional power on its propulsive power. lii an attack , lbr tho purposes of defence it would never bo far from its base, so that .tho question ' of the quantity of petrol to bo earned will not ooncern us hero. At night time it' would be especially dangerous, for it could steal impcrccived through the darkness upon its opponent, while the latter was kept "brilliantly lllummatc-d by searchlights seated on terra firma. Of course the aerostat also might carry a projector, dynamo, and engine, v etc., but at a great loss of ascensional power. It-is highly probable, in short, that, tho first 1 ' great aerial battle may follow very closely the lines laid down by Jules Verne in his' scientific romance of the '80'sl (Jules Vcrho's aeronel was a "helicoptere," a type which is attracting much, attention in the U.S.A.) If may bo objected that tho greatest height yet " reached by ,aiV-aeroplane was 125 ft;' or so, ' while; Zeppelin V easily rose to' 700 ft.,"but " this was 50 per'cent, greater than tho avia-' tor (Henry I'armnn) needed to attain to win the prize offered, in this connection, and developments in tlfis direction may.bo oxpect-ed as the experimenters gain moro 'confidence - in tho use of the particular machine they favour. Tho aeroplane, again, is not too hand.v when near the ground, but with amachine, of her—relatively—simple design there is no, need to outrage mechanical laws in attempting to removo "this' blemish. I The First Flying Machine. Meanwhile the people of tho United State! are hiostly occupied, > journalistically,' in proving that the real inventor of tho first fly- , mg machine was an American. Carl Dienstbach has broil contributing a series of articles to ono important magazine with this as a-text. Inter alia, he gives a striking picture of tho aerostat of tho future dia'gging a blazing tai!-ropo soaked in benzine m'ei a doomed town, 111 another pen-picture ii« ■ shows the airship dragging a. huge grapnel furnished with cutting appliances across tho deck of a hapless man-of-war (American Aeronaut), It is worthy of note that, in spit-o of'her , aerial triumphs, Germany has launched t<vti Dreadnoughts, and will bo laving down cwo more some time this year, while an Indomitable (larger than her prototype; is also under way. Thus it may bo taken as certain that tha day of aerostats has not yet come, and as i probable that when it does arrivo it will net : be of great duration.