Here is a patent for a trap bushing for radiators from F.J. Vaux in January 3, 1922. This one could easily stump you if you didn't know it was in there. Thanks to Steve Pajek for sharing this patent with us.
This chapter on hot water heating systems and piping was prepared by Professor F.E. Giesecke (Director of Texas Engineering Experiment Station in TX) for the The American...
Here are ratings for the Erie radiator from Jarecki Mfg Co Ltd. They were based in Erie, PA and their radiators appeared in issues of Domestic Engineering in the 1890s.
Brian Roberts & Paul Yunnie compiled this document that contains beautiful vintage advertisements and illustrations of radiators from the mid to late 1800s and early 1900...