English: A collection of colored fluorescent tube lamps, part of a display of new lighting ideas at the Westinghouse Lamp Division, Bloomfield, New Jersey, in 1944. Fluorescent lamps can be made in different colors by using different fluorescent coatings on the inside of the tube.
This 1944 issue of Popular Science magazine would have the copyright renewed in 1972. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. Search of the Renewals for Periodicals for 1967, 1968, and 1969 show no renewal entries for Popular Science. Therefore the copyright was not renewed and it is in the public domain.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.