Towcester Iron Co
1870-71 William Siemens tried again to use rotating furnace for making iron and steel by the direct process - he devised a new form of rotating furnace and erected 3 of them at Towcester, and tested them over several years.
The process was not commercially satisfactory, and the Towcester works were given up by Siemens in 1878
The works were subsequently carried on for the manufacture of spongy iron for filtering purposes.
Perhaps this was Spongy Iron and Purifying Co