US Patent 1,704,972, granted March 12, 1929 to Glenn D. Hurst of Los Angeles, describes a method and apparatus for keeping silk cocoons fresh for reeling. Instead of killing the chrysalis with heat, the cocoons are chilled with pressurized, humidity-controlled air at about 40\u00b0F and then held dormant in a storage chamber at about 45\u00b0F. This prevents the moth from emerging and breaking the filament, and preserves the silk's strength, elasticity and luster. The patent includes one drawing of the chamber, refrigeration, heating, humidity and blower units, followed by twelve claims.