One of the most sought after antique golf clubs, the Spalding Kro-Flite double waterfall Dedstop iron has a wavy pattern of large corrugated grooves on its face.  This rare club was offered only in Spalding's October 5, 1919 catalog.  According to the patent issued to William F. Reach, the wavy lines would allow the golfer to impart a great deal of backspin to both a direct stroke and cut shots. This is a patent applied for model (Reach applied for his patent on August 23, 1919). The head, shaft and grip are original.  The head has been nicely cleaned and shows minimal wear. A great example!

TCA2 Vol 1, p. 274-275.