Vol. 1 No.4 - Pg.1 - Col.2/3/4

AERIAL NAVIGATION.—The practicability of travelling rapidly and safely through the air, has been already established, as far as theory can establish a point without actual experiment; and the most important principles on which success in this mainly depends, have been already thus established. The specific gravity of hydrogen gas is less than that of atmospheric air, by something more than one ounce per cubic foot; and consequently a cubic foot of this gas being enclosed, has a buoyant power of one ounce in atmospheric air. A hollow globe, five feet in diameter, may be made of oiled silk of less than one pound weight; yet this globe, being filled with hydrogen gas, will possess a buoyancy in atmospheric air of more than four pounds. This sufficiently illustrates the first principles of ballooning; but as it is plain that a spherical balloon cannot be propelled with any considerable velocity on account of atmospheric resistance, we have adopted the eliptic spindle form, which will encounter—as will be proved in our next number,—less than 1-200th part as much resistance as a globe of equal diameter. A balloon of this figure, 350 feet in length and 35 in diameter, being inflated with hydrogen, will have acquired a buoyancy equal to 12,000 pounds. It will require in its construction 16 long rods, extending the entire length, and estimated to weigh 1000 pounds. 2,200 yards of strong linen cloth which, when varnished, will weigh 1000 pounds, thus leaving a balance of buoyancy of 10,000 pounds. An eliptic or revoloidal spindle-shaped saloon is attached to the balloon, being suspended immediately under it by cords or wires. It is covered with cloth, excepting about 100 feet of the central part, which has a permament floor and is ceiled with thin boards. The weight of this part of the apparatus is estimated at 3,000 lbs. We have already constructed and put in operation a steam engine and boiler capable of working two horse-powers, but weighing only 200 lbs., from which is is estimated that an engine and boiler, of a size to work two horse-powers, may be made within the weight of 1000 lbs. One or two spiral fan-wheels, of 16 feet diameter, together with the requisite machinery for communicating the power of the engine to the fan-wheel; and the requisite ropes and rigging connecting the saloon to the balloon, &c., may all be comprised within the weight of 1000 lbs.: thus leaving a balance of buoyancy of 5,000 lbs. for passengers, baggage, &c. A rudder consisting of two broad fans, intersecting each other at right angles in the centre, is attached to the stern end of the balloon, by a ball and socket, or universal joint. Four arms project in opposite directions from the rudder near its connecting joint; and from the ends of these, small lines extend to the interior of the saloon, and by means of which the direction of the balloon is completely governed, both horizontally and vertically. With regard to the velocity of this aerial ship, it is susceptible of demonstration, and will be shown in a future number, that ten horse-powers is sufficient to balance the atmospheric resistance at a velocity of 100 miles per hour: but if it were otherwise, there is sufficient buoyancy to admit of engines capable of producing 30 horse powers. This balloon being once inflated, is intended to be kept constantly afloat, being moored at about 100 feet distant from the earth, when not in use. When passengers are to be received or landed, the balloon will descend to within a few feet of the ground, and a light-seated car will descend with passengers, to receive them. When passengers are received, a corresponding weight of stone blocks will be deposited, and vice versa. The saloon will be furnished with an apparatus for the production of hydrogen, sufficient to supply whatever quantity may escape by leakage. The interior of the balloon will contain an arrangement of lines and pulleys, by which the circumference may be contracted sufficient to cause the balloon to descend whenever occasion requires. These lines, which are attached to the rods, and by which the rods are drawn towards the centre, are operated by a small iron rod or wire, which passes from the interior, down through a small stuffing box, to the saloon. By means of this rod and system, the vertical movement of the balloon will be principally governed. With regard to the safety of this mode of travelling, we think it can be readily made to appear that there will be less danger in travelling over land in aerial vessels, than there now ordinarily exists in travelling by either sailing vessels or steamboats. In the first place, the balloon will be less liable to accident, than either steam vessels or railroad cars on account of being less exposed; resting on the elastic atmosphere, and floating with the current, except what forward motion is given it by the propelling machinery, it cannot be effected by gales or squalls, like a stationary object, and its motions must be comparatively gentle. In the second place, the balloon will never soar so high burt that in case of accident, or any derangement of the machinery, it may safely descend to the earth, in ten minutes: an idea much more consolatory to the passengers, than that of being five hundred miles from land, and surrounded by a violently raging element, to which, in case of either fire or leakage, the marine passenger must commit himself. A third consideration is, that the balloon will be furnished with an improved parachute for each passenger, and of which each may avail himself in less than one minute, in case of any extra-ordinary emergency, and thus descend safely to terra firma, much easier than he could paddle himself to shore, on a cotton bale, even from the middle of Long Island Sound. The steam engine by which the balloon is propelled, will be very small, and the boiler being constructed of small copper tubes, there can be no possibility of damage by explosion; and no accident can possibly happen to the balloon, that would cause a sudden descent, so as to prevent the passengers from having sufficient time to avail themselves of the parachutes. Moreover, their baggage would all come to land in due time. We shall give further and more minute particulars on this subject, with sectional illustrations, and mathematical demonstrations; but these must be deferred for future numbers.