But an experiment with a safeguard to somewhat of this nature was attended with fatal consequence in the year 1824. A Mr. Harris, a lieutenant in the British Navy, ascended from the Eagle Tavern, City Road, with a balloon fitted with a contrivance of his own invention, consisting of a large hinged upper valve, having within it a smaller valve of the same description, the idea being that, should the operation of the smaller outlet not suffice for any occasion, then the shutter of the larger opening might be resorted to, to effect a more liberal discharge of gas.

Mr. Harris took with him a young lady, Miss Stocks by name, and apparently the afternoon--it being late May-- was favourable for an aerial voyage; for, with full reliance on his apparatus, he left his grapnel behind, and was content with such assistance as the girl might be able to render him. It was not long before the balloon was found descending, and with a rapidity that seemed somewhat to disturb the aeronaut; and when, after a re-ascent, effected by a discharge of ballast, another decided downward tendency ensued, Mr. Harris clearly realised that something was wrong, without, however, divining the cause. The story subsequently told by the girl was to the effect that when the balloon was descending the second time she was spoken to by her unfortunate companion in an anxious manner. "I then heard the balloon go 'Clap! clap!' and Mr. Harris said he was afraid it was bursting, at which I fainted, and knew no more until I found myself in bed." A gamekeeper tells the sequel, relating that he observed the balloon, which was descending with great velocity, strike and break the head of an oak tree, after which it also struck the ground. Hurrying up, he found the girl insensible, and Mr. Harris already dead, with his breast bone and several ribs broken. The explanation of the accident given by Mr. Edward Spencer is alike convincing and instructive. This eminently practical authority points out that the valve lines must have been made taut to the hoop at the time that the balloon was full and globular. Thus, subsequently, when from diminution of gas the balloon's shape elongated, the valve line would become strained and begin to open the valve, but in such a gradual manner as to escape the notice of the aeronaut. Miss Stocks, far from being unnerved by the terrible experience, actually made three subsequent ascents in company with Mr. Green.