MRS SUSAN R KNOX PAT APPL'D FOR: 6" high cone shaped, revolving stovetop sad iron heater that holds 4 irons. Four wheels rotate the heater. Sold by Hartzell's Auction Gallery at the Balestri Auction on 7/12/18 for $725.
"The devices to heat irons are as ingenious and as novel as the irons they heated." David Irons, Irons By Irons, page 145.