The pitch drop experiment | Make:
In 1927 Dr. Thomas Parnell at the University of Queensland heated a sample of petroleum pitch, also called bitumen, and poured it into a glass funnel, with a sealed neck, set in a ring stand. Three years later, in 1930, he broke the neck off the funnel and set it aside. It took eight years for the first drop of pitch to fall. The experiment has been running continuously ever since, and has produced a total of eight drops to date. The man shown in the photograph is Dr. John Mainstone, who is the experiment's current custodian.