Paul–Yes, the Hobbs patent was the one I was looking for. For some reason I had it in my mind that the wood shot capsule was patented by Mason. Thank you for the date.
To all the others who have noted U.M.C. shot loads with other than wood capsules, thank you for the information.
As most of you know I am working on compiling a complete list of all cartridges and loads listed in the E. Remington, U.M.C. and Remington Arms Co. catalogs. I have currently completed 1866-1905 and 2000-2007 and most of 1946-1985. This is a HUGE listing. The shot shell listing alone, up to 1905 is over 3500 different loading, NOT counting shot sizes.