What Are They Doing In This RPPC?

Hello all. I recently purchased a small lot of RPPCs, all taken in Japan around 1910-1930. This is one from that lot and I'm just curious about what the people in it might be doing. My best guess is digging/drilling a well, but that's only a guess. Any help is appreciated!



Zoomed in a bit:

I will take a wild guess! At first it looked like a big slingshot and I assumed they may be hand pile driving a casing for a core sample, as possible mineral exploration, or getting soil samples? But more than likley possible assist device for getting well water to the surface to irrigate fields as it looks like a wet casing at bottom under staging and I see the bucket at bottom right.

Yes, I agree w/ No1. It looks like it could be a rudimentary form of cable-tool drilling, essentially pounding the soil and rock within a casing, adding water as necessary, and then bailing the mud out, which allows the casing to settle to the finish depth where a well screen can be installed, and then the casing removed to expose the screen. Soil sampling for exploration is an alternative explanation.