Orchard frost protection using light bulbs

UCLA collections image via https://groups.io/g/RailroadCitrusIndustryModelingGroup/topic/104226356 . Photographer not identified.

Quinter Bashore holds a therapeutic lamp to help his orchard in Covina, 1939. Bashore stands on top of a barrel reaching above his head to adjust one of the lamps attached to a row of wires above his orchard.

Quinter Bashore has discovered a way to keep his orchards from being affected by cold weather due to his installation of 128 lights, 260 watts each, the kind used by physicians in electrotherapy.

Exposition Park, Los Angeles

Image: postcard with 1939 postmark

The rose garden at the park is in bloom. The University of Southern California is in the background.

All-American Canal

Image: United States Bureau of Reclamation photo from Library of Congress

1939 view of the Imperial Dam at the headwaters of the All-American Canal. The dam was completed in 1938 and the first water was delivered in 1940.

Excerpt from https://www.usbr.gov/projects/index.php?id=514:

The All-American Canal System, located in the southeastern corner of California, consists of the Imperial Diversion Dam and Desilting Works, the 80-mile All-American Canal, the 123-mile Coachella Canal, and appurtenant structures. The system has the capacity, through water diversions from the Colorado River at Imperial Dam, to irrigate about 530,000 acres of fertile land in the Imperial Valley and about 78,530 acres in the Coachella Valley.

X-raying of fruit

Images: from brochure distributed at 1939 Golden Gate International Exposition.

“…in the past it has been impossible to detect certain kinds of imperfection by external appearance alone. Frost damage and granulations in oranges…leave no indications on the surface…”

“This X-ray inspection unit permits the operator to look right through the fruit instead of at its surface only.”

Excerpts from the brochure.