Names
- Marconi, Guglielmo, 1874-1937--Portraits.1
- Mather, John A. (John Aked), 1829-1915.1
- Meigs, Montgomery, 1847-1931.1
- Menominee River Boom Company.1
- Meyer, C. J. L.1
- Minneapolis, St. Paul & Sault Ste. Marie Railway Company.1
- Mount Washington Cog Railway.1
- New York Elevated Railway Company.1
- Northern Pacific Railway Company.1
- Pennsylvania Railroad.1
- Radford, Edwin P.1
- Robbins, Frank, 1846-1924.1
- Rockefeller, John D., III (John Davison), 1906-1978--Portraits.1
- Roebling, John A. (John Augustus), 1806-1869--Portraits.1
- Roebling, Washington Augustus, 1837-1926--Portraits.1
- Smithsonian Institution.1
- Steinway & Sons.1
- Stephenson, George, 1781-1848--Portraits.1
- Stephenson, Robert, 1803-1859--Portraits.1
- Treadwell, T. K.1