as far back as the period of the napoleonic wars, the balloon was given a place in warfare, but up to the franco-prussian war of 1870–71 its use was intermittent. the federal forces made use of balloons to a small extent in the american civil war; they came to great prominence in the siege of paris, carrying out upwards of three million letters and sundry carrier pigeons which took back messages into the besieged city. meanwhile, as captive balloons, the german and other armies used them for observation and the direction of artillery fire. in this work the ordinary spherical balloon was at a grave disadvantage; if a gust of wind struck it, the balloon was blown downward and down wind, generally twirling in the air and upsetting any calculations and estimates that might be made by the observers, while in a wind of 25 miles an hour it could not rise at all. the rotatory movement caused by wind was stopped by an experimenter in the russo-japanese war, who fixed to the captive observation balloons a fin which acted as a rudder. this did not stop the balloon from being blown downward and away from its mooring station, but this tendency was overcome by a modification designed in germany by the parseval-siegsfield company, which originated what has since become familiar as the ‘sausage’ or377 kite balloon. this is so arranged that the forward end is tilted up into the wind, and the underside of the gas bag, acting as a plane, gives the balloon a lifting tendency in a wind, thus counteracting the tendency of the wind to blow it downward and away from its mooring station. smaller bags are fitted at the lower and rear end of the balloon with openings that face into the wind; these are thus kept inflated, and they serve the purpose of a rudder, keeping the kite balloon steady in the air.

an early type of the parseval-siegsfeld observation balloon.

used by the germans in russia.

an observation balloon about to ascend to watch enemy movements, near metz, 25th january, 1918.

various types of kite balloon have been introduced; the original german parseval-siegsfield had a single air bag at the stern end, which was modified to two, three, or more lobes in later varieties, while an american experimental design attempted to do away with the attached lobes altogether by stringing out a series of small air bags, kite fashion, in rear of the main envelope. at the beginning of the war, germany alone had kite balloons, for the authorities of the allied armies considered that the bulk of such a vessel rendered it too conspicuous a mark to permit of its being serviceable. the belgian arm alone possessed two which, on being put into service, were found extremely useful. the french followed by constructing kite balloons at chalais meudon, and then, after some months of hostilities and with the example of the royal naval air service to encourage them, the british military authorities finally took up the construction and use of kite balloons for artillery-spotting and general observation purposes. although many were brought down by gun-fire, their uses far outweighed their disadvantages, and toward the end of the war, hardly a mile of front was without its ‘sausage.’

for naval work, kite balloons were carried in a378 specially constructed hold in the forepart of certain vessels; when required for use, the covering of the hold was removed, the kite balloon inflated and released to the required height by means of winches as in the case of the land work. the perfecting of the ‘coastal’ and n.s. types of airship, together with the extension of wireless telephony between airship and cruiser or other warship, in all probability will render the use of the kite balloon unnecessary in connection with naval scouting. but, during the war, neither wireless telephony nor naval airships had developed sufficiently to render the navy independent of any means that might come to hand, and the fitting of kite balloons in this fashion filled a need of the times.

a necessary accessory of the kite balloon is the parachute, which has a long history. da vinci and veranzio (ante, page 119) appear to have been the first exponents, the first in the theory and the latter in the practice of parachuting. mongolfier experimented at annonay before he constructed his first hot air-balloon, and in 1783 a certain lenormand dropped from a tree in a parachute. blanchard the balloonist made a spectacle of parachuting, and made it a financial success; cocking, in 1836, attempted to use an inverted form of parachute; taken up to a height of 3,000 feet, he was cut adrift, when the framework of the parachute collapsed and cocking was killed.

in mid-air. a parachute descent from one of our balloons at the front, near metz, 26th january, 1918.

the rate of fall is slow in parachuting to the ground. frau poitevin, making a descent from a height of 6,000 feet, took 45 minutes to reach the ground, and, when she alighted, her husband, who had taken her up, had nearly got his balloon packed up. robertson, another parachutist, is said to have descended from a height379 of 10,000 feet in 35 minutes, or at a rate of nearly 5 feet per second. during the war brigadier-general maitland made a parachute descent from a height of 10,000 feet, the time taken being about 20 minutes.

the parachute was developed considerably during the war period, the main requirement, that of certainty in opening, being considerably developed. considered a necessary accessory for kite balloons, the parachute was also partially adopted for use with aeroplanes in the later war period, when it was contended that if a machine were shot down in flames, its occupants would be given a far better chance of escape if they had parachutes. various trials were made to demonstrate the extreme efficiency of the parachute in modern form, one of them being a descent from the upper ways of the tower bridge to the waters of the thames, in which short distance the ‘guardian angel’ type of parachute opened and cushioned the descent for its user.

for dirigibles, balloons, and kite balloons the parachute is an essential. it would seem to be equally essential in the case of heavier-than-air machines, but this point is still debated. certainly it affords the occupant of a falling aeroplane a chance, no matter how slender, of reaching the ground in safety, and, for that reason, it would seem to have a place in aviation as well as in aerostation.