Although much has been suggested, very little has been accomplished towards rendering balloons available for any practical use. Little has been done towards guiding a balloon. Many of the schemes which have been pro posed for the purpose evince a singular disre gard of the essential difference between a ship and a balloon. The former sails in two fluids of very different density, and the action of the water, the denser of the two, upon the rudder is a guide to the impelling power derived from the air, or lighter or less dense element; but no such regulator can be applied to the balloon, which is sustained, as well as im• pelled, by the air.
Mr. Green has been the most successful of our aeronauts. He was the first to introduce the use of common coal gas instead of hydro gen gas for the purpose of inflation, by which an immense saving of cost is effected, and the buoyancy of the balloon may be longer maintained, as it is far less liable to escape. Mr. Green, accompanied by Messrs. Holland and Monck Mason, made the remarkable voyage undertaken on the 7th of November, 1836, with the Great Nassau balloon. In tending to cross over to the continent, these voyagers started from Vauxhall Gardens, Lon don, at half-past one on the above-named day, crossed the Channel, continued their voyage through the night, and descended at half-past seven the following morning in the valley of Elbern, about two leagues from Weilburg, in the duchy of Nassau. The balloon with which this feat was performed is of silk, more than 60 feet high, and about 50 feet in diameter, and will contain, when fully distended, more than 85,000 cubic feet of gas.
We can hardly avoid an expression of regret that so much ingenuity should be still unpro fitably wasted on ballooning. Year after year contrivances are brought forward which have before been shown to be unsound in theory. In 1840 Messrs. Marsh and Ranwell suggested a complicated machine, consisting of a light metallic frame, to which about twenty small balloons were attached. Sir George Cayley has proposed a light kind of frame, exposing about 500 square feet of surface, to which some sort of steering apparatus is to be attached. Mr. Partridge has drawn attention to a machine which had somewhat the appear ance of an ovoid balloon ; with a complicated apparatus of sails and vanes ; and a steam engine fed with liquid fuel ! _at Eubriot, in 1839, made an oblong balloon, with a car pro vided with sails ; he expected that the car and sails would guide the balloon ; but when the machine was tried at Paris, the balloon guided the car, as it is the wont of balloons to do. Mr. Green himself, in 1840, exhibited a model at the Polytechnic Institution, of an apparatus which he expected would suffice to guide a balloon ; but we may conclude that nothing satisfactory has resulted. About ten
years ago, Dr. Polli, of Milan, suggested that the structure of a fish should form a model for an aerial locomotive ; but he was fore stalled in this obvious but fallacious idea, by other parties in England. In 1842 Mr. Benson took out his patent for that " aerial machine" which lived its little day of popularity, and then went out of sight ; a small steam-engine, in a car, was to propel a light framework 150 feet long ; and a tail 50 feet long was to serve as a rudder at one end ; but whether the machine could raise itself to a height, or could propel itself by the engine, or could steer itself by the tail, were enquiries never satisfactorily answered. Next came M. Monge's copper balloon, constructed at Paris in 1844; it was about 30 feet diameter, formed of sheet copper of an inch thick, weighed 300 lbs., and was capable of containing 100 lb. of hydrogen ; but of its success we have beard nothing. The egg-shape, the fish shape, the fan-shape, the kite-shape, all have been proposed, time after time, within the last few years; one of the latest being that of Mr. Bell, who recently patented two machines —a balloon motor, having both a sustaining and a propelling power; and a parachute motor, having a propelling power which con stituted its own sustaining power. The plan looked ingenious upon paper, but this is not very high praise.
Occasionally balloons are made subsidiary to science ; but very seldom. The British Association has more than once directed its attention to this matter, but with very little result. In 1843 Mr. Green made observa tions with meteorological instruments, at five different elevations, varying from 2591 to 677,8 feet; while Mr. Jones, the instrument maker, was making similar observations at the surface of the earth at the same time— such observations as these might perhaps be multiplied with advantage. Mr. Rush com municated to the British Association, in 1849, a series of thermometrical and barometrical observations, made during five balloon as cents, in 1847-8-9, at various altitudes ranging up to 20,000 feet. One of the latest sugges tions, for making balloons useful, was that recently made by the unfortunate Lieutenant Gale, for assistance in the search of Sir John Franklin.
During the recent ballooning season, it was stated that the number of recorded ascents exceeds 3000, of which the elder Green has made nearly 500 ; and that the ascertained fatal accidents do not amount to 20.
Of the sad foolery of ascending on the backs of horses, ponies, and other animals, nothing can be said but in condemnation. The last example was that in which Madame Poitevin, decked in white muslin and purple velvet, with a crown of roses on her head, ascended from the Champ de Mars on the back of a bullock!