of steel, connecting the screw with the pinion of a piece of spring machinery fixed in the car.  By the operation of this spring, the screw is made to revolve with great rapidity, communicating a progressive motion to the whole.  By means of the rudder, the machine was readily turned in any direction.  The spring was of great power, compared with its dimensions, being capable of raising forty-five pounds upon a barrel of four inches diameter, after the first turn, and gradually increasing as it was wound up.  It weighed, altogether, eight pounds six ounces.  The rudder was a light frame of cane covered with silk, shaped somewhat like a battledoor, and was about three feet long, and at the widest, one foot.  Its weight was about two ounces.  It could be turned flat, and directed upwards or downwards, as well as to the right or left; and thus enabled the æronaut to transfer the resistance of the air which in an inclined position it must generate in its passage, to any side upon which he might desire to act; thus determining the balloon in the opposite direction.

“This model (which, through want of time, we have necessarily described in an imperfect manner,) was put in action at the Adelaide Gallery, where it accomplished a velocity of five miles per hour; although, strange to say, it excited very little interest in comparison with the previous complex machine of Mr. Henson — so resolute is the world to despise anything which carries with it an air of simplicity.  To accomplish the great desideratum of ærial navigation, it was very generally supposed that some exceedingly complicated application must be made of some unusually profound principle in dynamics.

“So well satisfied, however, was Mr. Mason of the ultimate success of his invention, that he determined to construct immediately, if possible, a balloon of sufficient capacity to test the question by a voyage of some extent — the original design being to cross the British Channel, as before, in the Nassau balloon.  To carry out his views, he solicited and obtained the patronage of Sir Everard Bringhurst and Mr. Osborne, two gentlemen well known for scientific acquirement, and especially for the interest they have exhibited in the progress of ærostation.  The project, at the desire of Mr. Osborne, was kept a profound secret from the public — the only persons entrusted with the design being those actually engaged in the construction of the machine, which was built (under the superintendence of Mr. Mason, Mr. Holland, Sir Everard Bringhurst, and Mr. Osborne,) at the seat of the latter gentleman near Penstruthal, in Wales.  Mr. Henson, accompanied by his friend Mr. Ainsworth, was admitted to a private view of the balloon, on Saturday last — when the two gentlemen made final arrangements to be included in the adventure.  We are not informed for what reason the two seamen were also included in the party — but, in the course of a day or two, we shall put our readers in possession of the minutest particulars respecting this extraordinary voyage.