Screw size definitions

[Ray Keefer <Ray.Keefer@eng.Sun.COM>]

Hi,

[snip}
> Perry  boats turned 36 X 36 3-bladed bronze props (they weighed 175 pounds!)
> that  were driven by 10 hp 120V Reliance motors through reduction gears and 

[snip]
> memory serves with 17 to 1 gear  reduction. They turned a 28 X 24 bronze
> wheel and ran nearly 5 knots on the  surface. 
> 

Could someone explain the dimensioning to a prop? I assume "wheel" also meant
prop. Like:

36 x 36 3-blade Bronze
 |    |  |        |
 |    |  |         --->  Material it was made out of.
 |    |  |
 |    |	  ---> 3 blade
 |    |
 |     ---> ?
 |
  ---> 36inch diameter
		

Thanks,
Ray