I say "art" simply because the collecting of early wooden propellers is centered on an object that is graceful, pleasing to the eye and even sensual in appearance. Spencer Heath* in 1917 said referring to propellers, that "probably no other instrument in aeronautics has more nearly reached its ultimate development than the screw". Nothing, it turns out, could be further from the truth, as subsequent propeller designs soon assumed a more efficient but more monotonous design, the result being that all of the wooden propellers produced from the early twenties onward have have a similar (and rather "boring") general appearance. By achieving a higher level of "development" they have left the varieties of design of the teens and earlier in a category by themselves, characterised by elegant shapes and curves rather than two symetrical straight blades. In an effort to design the most efficient propeller early manufacturers experimented with a variety of distinctive airfoil designs. It is this aspect that first catches the eye, and makes early wooden propellers such desirable display artifacts.
Although production numbers of some of these early propellers were staggering, most of the early propellers were consumed during normal use. Others were unintentionally destroyed by well meaning efforts to mount clocks, or "improve" their appearance by refinishing, and many German propellers were ordered destroyed as a condition of the Armistace. As a result WW1 propellers in original condition are rare and difficult to find. Their uniques shapes, as shown by the graceful Sopwith Pup design on the left, are characteristic of a time period spanning no more than about 15 years, from the Wright brothers in 1903 to the end of WW1 in 1918. It is not surprising that their value has risen dramatically as they approach the true "antique" status of an item that is at least 100 years old.
I have been collecting early propellers as a hobby for the past 35 years. I still remember the excitement of buying my first one, a propeller that I would now consider "almost worthless" in comparison to what else has turned up over that time period. Like art however, the value of an individual work is primarily in the eye of the beholder, so for those who stumble across something that they like I've assembled a few links to hopefully help guide them through the process of acquiring and displaying wooden propellers in general.