Abstract
Observations on the normal storage of liquid hydrogen showed the evaporation rate and ortho‐para conversion rate to be consistent with those expected from a noncatalyzed reaction. A catalytic converter which gives 50 percent ortho when cooled with liquid air was installed in the feed‐gas line of a 25 1/hour hydrogen liquefaction plant. The decrease in storage loss is well worth the trouble of installation and operation of the converter.