Indiana University professor Rolla Harger invented the drunk-o-meter in 1938 - the very first stable breath-testing instrument to measure alcohol levels. The invention came at a time when alcohol was a major political issue. This was right at the end of the prohibition era, when the manufacturing, sale and transportation of alcohol were outlawed in the US.

To use the drunk-o-meter, the person being tested blew into a balloon. The air in the balloon was then released into a chemical solution. If there was alcohol in the breath, the chemical solution changed color. The greater the color change, the more alcohol in the breath. The level of alcohol in a person’s blood could then be estimated by a simple equation.

However, Dr. Harger’s invention was bested by another IU alumnus. In 1954, Robert Borkenstein, chairman of Indiana University’s department of police administration, invented a more portable tool called the Breathalyzer.