Peerless Manufacturing Type "M" Odorizer

In June 1937, Peerless Manufacturing of Dallas shipped its first Type "M" Odorizer. The metering gas odorizer was invented by Donald Sillers and Alexander Clarke in response to a tragic explosion in New London, Texas.

On Thursday, March 18, 1937, natural gas leaking beneath the London School caused an explosion that lifted the building into the air. Instantaneously, the school collapsed onto itself, trapping and crushing the students and staff inside. Nearly 300 students and teachers died that Thursday.

In the days following the tragedy, investigators determined that the odorless oxygen-gas mixture had accumulated undetected until a spark in the school's industrial-arts shop triggered the explosion. As a result of the explosion, the Texas Railroad Commission approved an order that all natural gas intended for domestic or industrial use had to be odorized.

Working together, Sillers and Clarke developed a device that would inject a precise amount of pungent chemical into natural gas flowing through it into transmission lines. The resulting strong sulfur smell warned all future natural gas users of a gas leak, saving countless lives.

The simple, efficient piece of engineering was recognized by the American Society of Mechanical Engineers as a National Historic Mechanical Engineering Landmark in 1992.