Page:Sim pall-mall-magazine 1904-01 32 129.pdf/19

 13 those at sea ; the dip is not brusquery arrested : so that the mind can anticipate the curve to its end, and there is no shock to give that queer "empty" sensation to the solar plexus. Furthermore, the shocks of a transatlantic liner are due to first the fore and then the after part of the giant construction rising out of the water to plunge into it again. The air-ship never leaves its medium—the air,—in which it only swings.

This consideration brings me to the most remarkable of all the sensations of aerial navigation. On my first trip it actually shocked me! This is the utterly new sensation of movement in an extra dimension.

Man has never known anything like free vertical existence. Held to the plane of the earth, his movement "down" has scarcely been more than to return to it after a short excursion "up," our minds remaining always on the plane surface even while our bodies may be mounting ; and this is so much the case that the spherical balloonist, as he rises, has no sense of movement, but gains the impression that the earth is descending below him.

Photo by Russell & Sons.

With respect to combinations of vertical and horizontal movements, man is absolutely without experience of them. Therefore, as all our sensations of movement are practically in two dimensions, this is the extraordinary novelty of aerial navigation, that it affords us experiences—not in the fourth dimension, it is true, but in what is practically an extra dimension—the third ; so that the miracle is similar. Indeed, I cannot describe the delight, the wonder and intoxication of this free diagonal movement onward and upward or onward and downward, combined at will with sharp changes of direction horizontally when the air-ship answers to a touch of the rudder ! The birds have this sensation when they spread their great wings and go tobogganing in curves and spirals through the sky!

The line of our great poet echoed in my memory from childhood. After this first of all my cruises I had it put on my flag.

It is true that spherical ballooning had prepared me for the mere sensation of height ; but that is a very different matter. It is therefore curious that, prepared on this head as I was, the mere thought of height should have given me my only unpleasant experience. What I mean is this.

The wonderful new combinations of vertical and horizontal movements, utterly out of previous human experience, caused me neither surprise nor trouble. I would find myself ploughing diagonally upward through the air with a kind of instinctive liberty. And yet when moving horizontally—as you would say, in the natural position—a glance downwards at the housetops disquieted me.

"What if I should fall?" the thought came. The housetops looked so dangerous, with their chimney-pots for spikes. One seldom has this thought in a spherical balloon, because we know that the danger in the air is nil : the great spherical balloon can neither suddenly lose its gas nor burst. My little air-ship balloon had to support not only exterior, but interior pressure as well, which is not the case with a spherical