Screw ships of prodigious size are now built and launched in all the ship-building ports of Britain, and are sent out to navigate in every part of the world.
The introduction of iron as the material for shipbuilding has immensely advanced the interests of steam navigation, as it enables the builders to construct vessels of great size with the finest lines, so as to attain the highest rates of speed.
One might have supposed that Francis Pettit Smith would derive some substantial benefit from his invention, or at least that the Ship Propeller Company would distribute large dividends among their proprietors.

Nothing of the kind.

Smith spent his money, his labour, and his ingenuity in conferring a great public benefit without receiving any adequate reward; and the company, instead of distributing dividends, lost about 50,000L.

in introducing this great invention; after which, in 1856, the patent-right expired.

Three hundred and twenty-seven ships and vessels of all classes in the Royal Navy had then been fitted with the screw propeller, and a much larger number in the merchant service; but since that time the number of screw propellers constructed is to be counted by thousands.
In his comparatively impoverished condition it was found necessary to do something for the inventor.