Great quote you found from the web :
....What we do know beyond a shadow of a doubt is that they were motivated to keep digging. If there was no flagstone, no platforms, no loose dirt and pick-ax marks along the walls of the pit, do you think they would have kept digging for a hundred feet? Just ask yourself the question, and let me remind you that these men were not retired or bored. They had families to feed and a lot of other hard work to be doing...
Let me address that this way, to use a real-life example:
There was some dude who bought either some sort of strange detector or LRL (I forget which exactly). After reading the instructions, he took it out in his yard to try it out. It gave an indication signal right in his yard ! So he began digging. The hole got bigger and bigger. But every time he'd turn the device back on to try again, he would keep indicating inside the hole. As if deeper. So he kept digging DEEPER. Convinced the device was telling him something was buried there.
Days went by, and he was now in over his head ! It got to where he couldn't continue with manual means, so he brought in some heavy equipment. At this point, neighbor's began to gawk. And the public works utility people were called. He was in some sort of violation of not getting permits (as this now constituted construction, or under-mining the street or sidewalk, or ... whatever. )
Whenever someone. his wife, etc... would ask him "Gee Bob, why are you digging this giant crater in your yard ?" He would just shoo them away. Fully convinced he was on to something big! The machine would beep or point or whatever each time he turned it on. Thus: Must mean treasure, eh ?
Eventually, the curious on-lookers, neighbors, city officials, etc... convinced him that ...... no ...... there was nothing there. And with tears in his eyes, he filled in this giant crater, worried that a treasure might have been "just out of his grasp".
Now ...... I hope you can see, that this guy was mistaken. I hope you can see that he was using the detector wrong (steel toed boots? etc...) or a magic wand LRL that was only snake oil in the first place, that simply tilts where you tilt it. In ANY case, that is an example of where .... yes ...... people can be UTTERLY convinced of a treasure, (even devoting their lives, calling in the media, hiring heavy equipment, etc...), where ........ truth be told: There was a more plausible explanation.
My reckless Theory of the Day
