Extract from "A Manual of the SteamEngine"
by R.H. Thurston 1891

Those of you interested in the mathematics of a sternwheel, or indeed
a radial (fixed float) sidewheel, take a gander at this little gem.

http://www.steamgoon.steampower.net/books.html

PJ

What a splendid "find", PJ.
Interestingly on page 188 it gives the slip for a paddle at only 15.37%
whereas the slip for the screw is given as 26.20%. I think that screw design
must have come quite a long way since then. I seem to remember that when I
was at sea, we used to record somewhere about the same figure as is given
for the paddle.
Also interesting that a paddle looses 18.00% as "oblique action". Was that
for feathering or fixed floats ? One has to wonder how they came up with
such accurate figures (two decimal places!)!! Must have been mighty
difficult to measure some of these forces and losses!!
Happy paddling.
David