“...because not much could go wrong with giant concrete arrows on the ground. According to the Assistant Postmaster-General of the time, as quoted in the December 1923 issue of Popular Mechanics, there was a plan to build a similar system over the Atlantic.”
I looked for the big concrete arrows on the Atlantic ocean on Google Earth. Didn’t find them. In re-reading the article I see that those were just proposed. Silly me. ;)
So in toto that group symbolizes “Large breast ahead” ?