rotative pumping engines of large size have a plunger speed of 90 ft. per minute.
If it is a rotative engine, with a winding barrel, it will cost 270l.
The rotative speeds of turbines, operating under any given head, should thus increase as their capacities and diameters decrease.
I do not say, "The tables turn because my fluid is rotative."
Watt had perfected, with the aid of Murdoch, both the pumping-engine and the rotative steam-engine for application to mills.