POLYPROPYLENE
November 12, 1999 - Bartlesville, Oklahoma, U.S.A.
In Bartlesville, Oklahoma, a plaque was placed on the site of the laboratory where the polymer polypropylene was invented, designating it a National Historic Chemical Landmark by the American Chemical Society. The first commercially successful use of the new material was in the Hula Hoop®. In 1951, J. Paul Hogan and Robert L. Banks, research chemists working for Phillips Petroleum Company, discovered the polymer unexpectedly during experiments with catalysts while trying to convert the natural gas components ethylene and propylene into compounds useful for gasoline. Later, they also developed a new catalytic process for making high-density polyethylene. Phillips soon invested in new plastic manufacturing plants.
PITOT TUBE
November 12, 1732 - Academy of Sciences, Paris
Henri Pitot read a paper to the Royal Academy of Sciences in Paris about an instrument he had invented to measure the flow velocity at different depths of water in the River Seine. It had a scale and two open vertical glass tubes on a wood frame. The lower end of one pointed down, the other bent at 90 facing the flow. The belief of the time was that flow velocity at a given depth was proportional to the mass above it, meaning increasing velocity at greater depth. Recording the difference in liquid levels in the two tubes, he showed the opposite was true. Henri Darcy improved the design, with the support of Henri Bazin. Today, the Pitot tube has an important application in aerodynamics for the measurement of the airspeed of aircraft.