He made haste to get the end off his wrist, and saw it fly through the little hole in the window frame, and away after the rest of it, to be wound on the whirling spool.
Disappointing as this was, however, there was progress in it: he had got the thing to work, and all that remained was to regulate it.

But this turned out the most difficult part of the affair by far.

He saw at once that if he were only to make the thread longer, which was the first mode that suggested itself, he would increase the constant danger there was of its getting fouled, not to mention the awkwardness of using such a quantity of it.

If the kitten were to get into the room, for instance, after he had laid it down, she would ruin his every hope for the time being; and in Willie's eyes sixpence was a huge sum to ask from his father.

But if, on the contrary, he could find out any mode of making the machine wind more slowly, he might then be able to shorten instead of lengthening the string.
At length, after much pondering, he came to see that if, instead of the spool, he were to fix on the axis a small cogged wheel--that is, a wheel with teeth--and then make these cogs fit into the cogs of a much larger wheel, the small wheel, which would turn once with every turn of the water-wheel, must turn a great many times before it could turn the big wheel once.