Subject
- Richards, Ellen H. (Ellen Henrietta), 1842-19111
- Rillieux, Norbert, 1806-18941
- Rivers1
- Rocky Flats Plant (U.S.)1
- Rohm and Haas Company1
- Rorer, S. T., 1849-19371
- Roscoe, Henry E. (Henry Enfield), 1833-19151
- Rosenkranz, George, 1916-20191
- Röntgen, Wilhelm Conrad, 1845-19231
- Rubber1
- Rubber Growers' Association1
- Rubber goods1
- Rumford Company1
- Sabin, Alvah Horton, 1851-19401
- Saccharin1
- Sacks, Oliver, 1933-20151
- Salt industry and trade1
- Sanitary engineering1
- Sanitary engineers1
- Saville, Dudley1