In practice the ascensional force usually diminishes at first from various causes, such as the escape of gas, its cooling, and the deposit of moisture on the outside of the balloon.
Pétin computes, of twelve hundred horse-power, we should still have at command a surplus ascensional force of upwards of ninety millions of pounds; a force sufficient to sustain a body of fifty thousand men!
In fact, this assumption of the possibility of obtaining command of an unlimited ascensionalforce has suggested, to certain enthusiastic partisans of M.
The theory of the ascensionalevolution of beings, which renders miracle useless, shows Nature to us in the course of constant transformation and perpetual travail.
In a very little while, the gas expanded under the action of the heat, and the balloon took a very decided ascensional movement.
We shall have mountains to pass, and that will be difficult to do, since I cannot augment the ascensional force of the balloon, even with the greatest possible heat that I can produce.
At this moment the ascensional force of the balloon increased prodigiously, and Ferguson, Kennedy, and Joe, waved a last good-by to their friends.
The doctor was aware that, by the loss of the hydrogen in the first balloon, the ascensional force at his disposal was now reduced to about nine hundred pounds.
Joe, slipping nimbly down the tree, carefully attached the anchor, and the doctor left his cylinder at work to a certain degree in order to retain sufficient ascensional force in the balloon to keep it in the air.
Thus the Victoria found herself balanced, and her ascensional force insufficient to raise her.
Dick had better remain, therefore, in the car, and keep the cylinder warm so as to secure a sufficient ascensional force for the balloon.
All that was necessary was to get above this bed of mist, which was nearly thirteen hundred feet thick, and the ascensional screws being increased in speed, the "Albatross" was soon clear of the fog and in the sunny regions of the sky.
It was necessary to increase the ascensionalpower to prevent her falling into the sea.
An extreme ascensional power was communicated to the aeronef, and she shot up slantingly as if she was traveling on a plane sloping downwards from the southwest.
But hydrogen possesses an ascensional force estimated at 1,100 grams per cubic meter.
If you will give a column of air an ascensionalmovement of forty-five meters a second, a man can support himself on the top of it if the soles of his boots have a superficies of only the eighth of a square meter.
The ascensional movement did not cease until the "Go-Ahead" had reached a height of fourteen thousand feet.
Her ascensional power was due to the very lightest of gaseous bodies.
The balloon regained its ascensional force, but soon re-descended.
Nevertheless, the rays of the sun fell hotly on the globe, and, dilating the gas it contained, gave it a greater ascensional force.
A cork held down at the bottom of a vessel of water and then left to itself will supply an example of this ascensional movement.
Oliphant wrenched at the lever; Tom put the whole force of the second engine upon the ascensional screws; and the rapidity of descent was somewhat checked.
While speaking, he had stopped the ascensional screws and set the horizontal going.
The two mounted the car; Tom started the ascensional screws; and the airship rose slowly from the hill.
But as soon as his weight was supported by the water, the ascensional screw, now set by Tom whirling at full speed, checked the downward movement, and in another couple of seconds the airship began to rise, dragging the youth upwards.
Then, entering the car in which Schwab and Oliphant already were, he set the ascensional screws in motion.
He knew from experience that with Schwab as a passenger the ascensional screws did not exert sufficient power to lift three other men; but when Oliphant had reminded him of this, a way out of the difficulty suggested itself.
The airship was now only about sixty feet above the sea, and before Tom, his attention partly engaged by the efforts of the boy, could increase the speed of the ascensional screw, the light vessel was pulled swiftly downwards.
Then he started the ascensional screw, and with a whirr like that of a gigantic humming-top the airship rose slowly from the yacht's deck.
When brought still lower, its ascensional force increased and the front of the aerobike pitched downward.
The ascensional rudder or screw-propeller, which was able to impart a speed of thirty miles an hour to the machine, was in the extension of the horizontal bar of the frame.
By following the ascensional path of the projectiles as revealed by the smoke it was possible to draw certain conclusions.
The rapid ascensional capability of the airship, as compared with that of the aeroplane, is a disadvantage, but on the other hand, the superior mobility and speed of the aeroplane would tell decisively for success.
The latest types of this craft are said to possess a high ascensional speed, which offers a distinct protection against aeroplane attack.
This is far in excess of the ascensional speed of even the speediest aeroplane, of course, the penalty for such a factor has to be paid: the loss of gas is appreciable and may lead to the craft's ultimate undoing.
It had left the balloon house imperfectly inflated, hence it lacked ascensional force.
Moreover, the ascensional force of the balloon is regulated accordingly: it is very little if the wind be light; it is more if the wind be stronger.
When the weighing and balancing of the balloon are finished and the aeronauts have taken their place in the basket the balloon is ready to quit the ground with a certain ascensional force.
All that I can remember is, that on every ascensional motion, we were hoisted up with ever increasing velocity, as if we had been launched from a huge projectile.
Nevertheless, while we were speaking we were still ascending; we passed the whole night going up, or to speak more scientifically, in an ascensional motion.
