A Maine man was called from the hayfield to wash out the clothes for his invalid wife.

He had never realized what it was to wash before.

He invented the washing-machine and made a fortune.

A man who was suffering terribly with toothache, said to himself, "There must be some way of filling teeth to prevent them aching;" he invented gold filling for teeth.
The great things of the world have not been done by men of large means.
Want has been the great schoolmaster of the race: necessity has been the mother of all great inventions.

Ericsson began the construction of a screw-propeller in a bath-room.