Cox was in the U.S. Navy, so he may be talking only about mineral wool marine insulation. Here is what he said in 1937: p.476 "The rock wool type [of insulation] is composed of nodulated rock wool fibers, clay, and asbestos fibers. This type generally can be easily applied and will adhere to any clean, unheated or heated surface." The 1948 J-M article suggests, but does not state, that there was at least some asbestos in the manufacture of rock wool used in homes. There was a JM mineral wool plant in Asbestos, Quebec that used local stone as stock (on this point, see also Goudge, M. F. "Rock wool." 623-34. Montreal, Canada: Canadian Institute of Mining and Metallurgy, 1936). p.76 "The other type of rock wool manufactured at Toronto is the batt, used for insulating new homes while they are under construction. By the advanced manufacturing process used at Toronto, long, fine fibres of rock wool are felted into light, resilient batts, uniform in insulating efficiency." The 1974 Winer article abstract says that "A mineral wool of good quality was prepared from a 70:30 mixture of chrysotile asbestos tailings and a local sand from the Eastern Townships of Quebec. A nickeliferous by-product (5% nickel) was recovered, which could be credited to process costs. A preliminary market study and capital costing of the process indicate a viable operation, returning over 20 per cent on investment before taxes." Another source on this issue is Thornbury, William D. "Mineral wool industry of the United States." Economic Geography 14, no. 4 (1938): p.404 "Other forms in which mineral wool is produced are: rock wool cement (mixed with asbestos or clay); pads; panels; plaster; brick; felt; cork board; and, acoustic blankets, pads, and panels." Hausdok, as to your Seattlites, take a look at http://www.resasb.org/. Mineral, rock and slag wool producers have been put into bankruptcy by asbestos litigation. rpm
