Silkhands - you post sounds like something that came out of the Monty Python school of logic. Whatever those pills are that you are taking, stop it.
SixDemonBag - In reference to square tip vrs round tips. Yes, they produce more drag, BUT, if you are trying to put the maximum amount of power into a propeller, for a given rpm and pitch, and assuming a constant number of blades, you can only then increase the area of blade. If you have already reached the limiting diameter (i.e. trans-sonic tips), that only leaves increasing the blade's chord, or it's camber. Square tips are an improvement in the former. Square tips = "wider" chord = more area = more thrust (just like a helicopter blade). For a given blade diameter, a round tip prop cannot produce the same thrust as a square tip, unless it has a wider chord elsewhere. It is however, like everything, a compromise.
The peculiarities of the engine it is mated to is a big factor in chosing the design, as is it's anticipated operating environment. A given aircraft might perform better using square tips instead of round tips, because of the power curve characteristics of the engines and the flight envelope and role of the aircraft itself. As Checkboard points out, a big avantage of a square tip is it's resilience to stone chips (perhaps SFTOL operations), and ease/economy of manufacture.
It's clearly a case of horses for courses.
[This message has been edited by Weary (edited 07 September 2000).]
[This message has been edited by Weary (edited 07 September 2000).]