The first thing I did was to buy a strong leathern knapsack, and inside of this I fastened my little machine, with a screw so arranged that it could be worked from the outside. Strapping this firmly to my shoulders, my wife gently turned the screw at the back until the upward tendency of the knapsack began to lift and sustain me. When I felt myself so gently supported and upheld that I seemed to weigh about thirty or forty pounds, I would set out for a walk. The knapsack did not raise me from the ground, but it gave me a very buoyant step. It was no labor at all to walk; it was a delight, an ecstasy. With the strength of a man and the weight of a child, I gayly strode along. The first day I walked half a dozen miles at a very brisk pace, and came back without feeling in the least degree tired. These walks now became one of the greatest joys of my life. When nobody was looking, I would bound over a fence, sometimes just touching it with one hand, and sometimes not touching it at all. I delighted in rough places. I sprang over streams. I jumped and I ran. I felt like Mercury himself. I now set about making another machine, so that my wife could accompany me in my walks; but when it was finished she positively refused to use it. "I can't wear a knapsack," she said, "and there is no other good way of fastening it to me. Besides, everybody about here knows I am no walker, and it would only set them talking." I occasionally made use of this second machine, but I will give only one instance of its application. Some repairs were needed to the foundation-walls of my barn, and a two-horse wagon, loaded with building-stone, had been brought into my yard and left there. In the evening, when the men had gone away, I took my two machines and fastened them, with strong chains, one on each side of the loaded wagon. Then, gradually turning the screws, the wagon was so lifted that its weight became very greatly diminished. We had an old donkey which used to belong to Herbert, and which was now occasionally used with a small cart to bring packages from the station. I went into the barn and put the harness on the little fellow, and, bringing him out to the wagon, I attached him to it. In this position he looked very funny with a long pole sticking out in front of him and the great wagon behind him. When all was ready I touched him up; and, to my great delight, he moved off with the two-horse load of stone as easily as if he were drawing his own cart. I led him out into the public road, along which he proceeded without difficulty. He was an opinionated little beast, and sometimes stopped, not liking the peculiar manner in which he was harnessed; but a touch of the switch made him move on, and I soon turned him and brought the wagon back into the yard. This determined the success of my invention in one of its most important uses, and with a satisfied heart I put the donkey into the stable and went into the house.