US1639908 // US1753252
Modern Mechanics & Inventions (May 1935)
US1639908 // US1753252
Modern Mechanics & Inventions (May 1935)
US1,963,676
Modern Mechanics & Invention (October 1934)
US2,090,052 // US2,045,233
Modern Mechanics & Inventions (May 1935)
US2,004,256
