Patent Number 2,857,648 "Method of Making a Seamless Conduit," John J. March, filed Oct. 28, 1957

Patent Number 2,857,648 "Method of Making a Seamless Conduit," John J. March, filed Oct. 28, 1957, Box: MORE008, Folder: 23. Frank L. Moreland collection, MORE. Alexander Architectural Archives. https://archives.lib.utexas.edu/repositories/2/archival_objects/85733 Accessed September 25, 2026.