Lin Mo wanted to rush in immediately, but he held back.
He still had common sense,
sealed underground spaces usually had high levels of carbon dioxide, and could also produce very toxic hydrogen sulfide gas.
Rushing in rashly could easily lead to unconsciousness and death.
In Lin Mo's hometown, it was also common to dig cellars for storing ginger; every couple of years one would hear news of someone dying after going into a cellar.
The countermeasure was simple.
Lin Mo went back to the surface, found the blower he had bought earlier, connected the outlet to a plastic tube, then dropped the tube into the well to start supplying oxygen.
How to determine if there was enough oxygen?
This was even simpler,
Tie a basket to a rope, put a burning candle in the basket, and lower the candle bit by bit.
If the candle didn't go out, it meant there was enough oxygen below.
