When his first baby was born, Bradley invented a self-rocking cradle for it.  He constructed the motive-power of the machine from some old clockwork which was operated by a huge steel ribbon spring strong enough to move a horse-car and long enough to run for a week without rewinding.  When the cradle was completed, he put the baby in it upon a pillow and started the machinery.  It worked beautifully, and after watching it for a while Bradley went to bed in a peaceful and happy frame of mind.  Toward midnight he heard something go r-r-r-rip!  Buzz-z-z-z!  Crash!  Bang!  Then a pin or something of the kind in the clockwork gave way, and before Bradley could get out of bed the cradle containing the baby was making ninety revolutions a minute, and hopping around the room and slamming up against the furniture in a manner that was simply awful to look at.

[Illustration:  BRADLEY’S CRADLE]

How to get the child out was now the only consideration which presented itself to the mind of the inventor.  A happy thought struck him.  He took a slat out of the bedstead and held it under the cradle.  On the next down-stroke it stopped with a jerk, and the baby was thrown, like a stone out of a catapult, against the washstand, fortunately with the pillow to break its fall.  But the machine kept whizzing round and round the room as soon as the slat was withdrawn, and Bradley, in an ecstasy of rage, flung it out the back window into the yard.  It continued to make such a clatter there that he had to go down and pile up barrels and slop-buckets and bricks and clothes-props and part of the grape-arbor on it, so that all it could do was to lie there all night buzzing with a kind of smothered hum and keeping the next-door neighbors awake, so that they pelted it with bootjacks, under the impression that it was cats.

Mrs. Bradley expressed such decided views respecting cradles of that pattern that Mr. Bradley turned his attention to other matters than those of a domestic character.  He resolved to revolutionize navigation.  It occurred to him that some kind of an apparatus might be devised by which a man could walk upon the surface of the water, and he went to work at it.  The result was that in a few weeks he produced and patented Bradley’s Water Perambulator.  It consisted of a couple of shallow scows, each about four feet long.  These were to be fastened to the feet; and Bradley informed his friends that with a little practice a man could glide over the bosom of a river with the ease and velocity with which a good skater skims over the ice.

It looked like a splendid thing.  Bradley said that it would certainly produce a revolution in navigation, and make men wholly independent of steamers and other vessels when they desired to travel upon water with rapidity.  Bradley intimated that the day would come when a man would mount a water perambulator and go drifting off to India, sliding over the bounding billows of the dark blue sea as serenely as if he were walking along a turnpike.