Gao Linzhi didn't dig straight down. He headed east first, then west.
His hands were like a tunneling machine, incredibly sturdy.
The hard limestone was no different from tofu in front of him.
A 5+400 base constitution—eighty times that of an ordinary person!
By a simple estimate, the average person had a density of one gram per cubic centimeter, about the same as water.
Eighty times that was eighty grams per cubic centimeter. Even gold, which was extremely dense, was only nineteen grams per cubic centimeter!
You could say that the density of nearly every substance on Earth was far below the strength of Gao Linzhi's body now.
Using density alone to measure strength wasn't very rigorous. Gold, for instance, was quite soft. Still, it was a decent comparison.
He worked quickly, digging more than half a kilometer in just over an hour!
That was far faster than industrial equipment.
A tunneling machine, for instance, usually moved at a speed of six to ten meters per hour.
Industrial equipment also had to deal with removing the rubble and preventing cave-ins. He only had to store the debris in his backpack.
After digging more than half a kilometer, Gao Linzhi began to dig downward.
Digging down was more troublesome.
After he'd dug fifty meters, the tunnel collapsed.
It buried him, but with a constitution eighty times that of an ordinary person, he was as comfortable among the rocks as he would have been in water.
As for breathing, that wasn't a problem.
He could last at least 240 minutes—that is, more than six hours.
His improved constitution enhanced every aspect of his body.
He was now one of the Zu Guo People!
He continued digging deeper.
One hundred, two hundred, three hundred meters!
The pressure on him grew greater and greater.