I had performed every evolution prescribed by the problem. The breakdown itself had not been due to any cause foreseen by the professional aeronauts.

I had mounted without sacrificing ballast. I had descended without sacrificing gas. My shifting weights had proved successful, and it would have been impossible not to recognise the capital triumph of these oblique flights through the air. No one had ever made them before.

Of course, when starting, or shortly after leaving the ground, one has sometimes to throw out ballast to balance the machine, as one may have made a mistake and started with the air-ship far too heavy. What I have referred to are manœuvres in the air.

"No. 4" FREE DIAGONAL MOVEMENT UP

"No. 6." FREE DIAGONAL MOVEMENT DOWN

My first impression of aerial navigation was, I confess, surprise to feel the air-ship going straight ahead. It was astonishing to feel the wind in my face. In spherical ballooning we go with the wind, and do not feel it. True, in rising and descending the spherical balloonist feels the friction of the atmosphere, and the vertical oscillation makes the flag flutter, but in the horizontal movement the ordinary balloon seems to stand still, while the earth flies past under it.

As my air-ship ploughed ahead the wind struck my face and fluttered my coat, as on the deck of a transatlantic liner, though in other respects it will be more accurate to liken aerial to river navigation with a steamboat. It is not like sail navigation, and all talk about "tacking" is meaningless. If there is any wind at all it is in a given direction, so that the analogy with a river current is complete. When there is no wind at all we may liken it to the navigation of a smooth lake or pond. It will be well to understand this matter.