Moreover, just as Lin Yi was observing, with his movements, there was a rustling sound coming from inside.
This made Lin Yi instantly direct his gaze towards the opening of the iron sphere.
He saw that on this iron sphere, there was indeed a tiny circular hole, which was not particularly large, about the size of a modern beer bottle cap.
And as he brought his eyes closer, he immediately saw that it was filled with half-spheres of iron nails, Iron Nails, and the like.
Seeing this, Lin Yi couldn't help but nod in satisfaction, as this was exactly what he had instructed Tie Niu to do.
"Not bad, not bad. How deep is this groove on top? And how thick is it from the inner wall?"
After nodding in satisfaction, Lin Yi turned his attention to the crisscrossed grooves on the outer surface of the iron sphere.
Upon hearing this, Tie Niu didn't even think before responding:
"It's only as thick as a large coin on the inside."
Hearing this, Lin Yi couldn't help but feel astonished.
