Underground antennas

While researching the W8NYY call sign written in the 1937 ARRL Handbook I picked up, I came across a NOARS (Northern Ohio Amateur Radio Society) newsletter from March 2019 with a column by W8GWD answering a question about underground antennas. In it, he references an article from a March 1948 QST (a typo in the newsletter gives it as May 1948) by Paul Cornell/W8EFW who wrote about his investigations into rumours of buried antennas. W8EFW related a conversation with W8NYY who worked W8RJF, who was using an underground antenna

One day, while having lunch with W8NYY at Akron, Ohio, Lloyd told me that he had worked W8RJF in Cleveland, on 10, and that RJF mentioned that his antenna was buried in the ground.”

Underground Antennas: Are they fact or fiction? – Paul Cornell W8EFW March 1948 QST

W8EFW goes on to talk about meeting W8RJF to learn more about his underground antenna: a doublet fed through some garden hose and buried 4-5 feet underground.

An editor’s footnote in W8EFW’s article mentions a letter in the May 1925 QST where 5Rx/5XAY describes using a wire antenna buried one foot underground and operating on 80, 50, and 40m.

I’ve heard of antennas on the ground (such as a BOG/Beverage On Ground) but the idea of underground antennas is a new one to me. Apparently some have been used on the 2200 and 630m bands. Now I’m intrigued. I need to dig into this some more.