Treasure Hunting Before Metal Detectors
Below are two articles that give first hand accounts of what treasure hunting looked like before metal detectors became widely available to the public. The first article shows that it was widely known that rings drop off while swimming. You will read references to a coal sieve being used to sift through the early 1900's sand.
The Brooklyn Daily Eagle
03 Dec 1913, Wed · Page 4

The second article describes people finding 25 dollars per day in change at the start of The Great Depression in 1930.
The Brooklyn Daily Eagle
25 Sep 1930, Thu · Page 15
