John V. N. Dorr

John Van Nostrand Dorr (January 6, 1872 – June 29, 1962) was an American industrial chemist and inventor. He is known for developing industrial chemical techniques, like the Dorr classifier, Dorr thickener, and Dorr agitator. He founded Dorr Foundation, which conducted research in the 1950s on the effectiveness of painted lines on road shoulders and its impact on highway safety.

Early life John Van Nostrand Dorr was born on January 6, 1872, in Newark, New Jersey, to Nancy H. (née Higginson) and John Van Nostrand Dorr. He was taught by his mother, who was founder of the Riverside School in Wallingford, Connecticut. She encouraged Dorr to hike and explore iron and copper mines in New Jersey and to collect specimens.

From 1888 to 1890, Dorr worked in Thomas Edison's laboratory in West Orange, New Jersey, as a chemist and experimenter. He later became a vice president of the Edison Pioneers. He then learned the cyanide process and spent some time in Colorado before returning to Deadwood. In 1902, he started a partnership with John Lundberg, a mine leaser, and together they operated the Rossiter Mill, a cyanide mill in Fantail Gulch. By 1926, his office was on Park Avenue in New York City. At Dorr's suggestion, the state of Connecticut painted lines on the shoulder of a stretch of the Merritt Parkway near Greenwich. By 1956, the entire length of Merritt Parkway had its shoulders painted. In 1926, he lived on Park Avenue in New York City. He received the Chemical Industry Medal in 1938 and the Perkin Medal by the Society of Chemical Industry in 1941. In 1949, the Chemical Engineering Magazine wrote that Dorr's inventions were "probably greater than those of any other chemical and metallurgical engineer of our times".