This bulletin on horses and horsepower from 1926 is pretty great, though it also doesn't answer the question very clearly: https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1466&...
There's a bunch of load pull tests there, but they are only done on teams, never on a single horse.
This bulletin on horses and horsepower from 1926 is pretty great, though it also doesn't answer the question very clearly: https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1466&...
There's a bunch of load pull tests there, but they are only done on teams, never on a single horse.