From its very introduction and inception the gas balloon, an expensive and fragile structure in itself, had proved at all times exceedingly costly in actual use. Indeed, we find that at the date at which we have now arrived the estimate for filling a balloon of 70,000 cubic feet--no extraordinary capacity--with hydrogen gas was about L250. When, then, to this great outlay was added the difficulty and delay of producing a sufficient supply by what was at best a clumsy process, as also the positive failure and consequent disappointment which not infrequently ensued, it is easy to understand how through many years balloon ascents, no longer a novelty, had begun to be regarded with distrust, and the profession of a balloonist was doomed to become unremunerative. A simpler and cheaper mode of inflation was not only a desideratum, but an absolute necessity. The full truth of this may be gathered from the fact that we find there were not seldom instances where two or three days of continuous and anxious labour were expended in generating and passing hydrogen into a balloon, through the fabric of which the subtle gas would escape almost as fast as it was produced. It was at this juncture, then, that Charles Green conceived the happy idea of substituting for hydrogen gas the ordinary household gas, which at this time was to be found ready to hand and in sufficient quantity in all towns of any consequence; and by the day of the coronation all was in readiness for a public exhibition of this method of inflation, which was carried out with complete success, though not altogether without unrehearsed and amusing incident, as must be told.