Discovery of Helium in Natural Gas: A Retrospective

A very interesting insight into the evolution of helium production and personal insights into the life and contributions of H. P. Cady was presented by his grandson, Dr. Ralph Cady Longsworth, retired from APD Cryogenics, in a paper entitled “100th anniversary of the discovery of helium in natural gas,” presented at the Cryogenic Engineering Conference in 2005. This article is excerpted from that paper with the author’s permission.

Superfluid Helium in Space

Many scientific observations must be done in space at cryogenic temperatures a few millidegrees to a few degrees above absolute zero (-273°C). These include observations of the behavior of superfluid helium in space and observations with instruments and millimeter-wave telescopes operating at liquid helium temperatures.