he became more and more convinced that he was right. When the rough
sketch was done he looked up at the engine. Its familiar features seemed
to be drawn into a diabolical grimace of contempt at his stupidity, and
it looked as if it were conscious and wanted to throw the wrongly-made
piece at his head. But he was overwrought just then and could have
fancied any folly.

He rose, shook himself, and then took a long pull at a black bottle that
always stood on a shelf. When a man puts a black bottle to his lips,
tips it up, and takes down several good pulls almost without drawing
breath, most people suppose that he is a person of vicious habits. In
Overholt's case most people would have been wrong. The black bottle
contained cold tea; it was strong, but it was only tea, and that is the
finest drink in the world for an inventor or an author to work on. When
I say an author I mean a poor writer of prose, for I have always been
told that all poets are either mad, or bad, or both. Many of them must
be bad, or they could not write such atrocious poems; but madness is
different; perhaps they read their own verses.

When Overholt had swallowed his cold tea, he got out his drawing
materials, stretched a fresh sheet of thick draughtsman's paper on the
board, and sat down between the motor that would not move and the
little city in which Hope had taken lodgings for a while, and he went to
work with ruler, scale and dividers, and the hard wood template for
drawing the curves he had constructed for the tangent-balance by a very
abstruse mathematical calculation. That was right, at all events, only,
as it was to be reversed, he laid it on the paper with the under-side
up.

He worked nearly all night to finish the drawing, slept two hours in a