Clarence studied the knowledge in the books for nearly ten hours without losing focus. He was just that enamored with it. By the end of it, he knew that the majority of the devices made by that power ran on electricity.
It was a tamer version of lightning power the cultivators used and specialized in. There were also these weapons which worked on just pure placement of different parts and gunpowder.
It amazed him how even little things such as these when used at the right time and place amplify the end result so much.
By the end of it, when he just opened his eyes after going through all the information of books transferred to his brain, he realized one thing,
'Wait… the description of that weapon never mentioned it would hide me from mana sense.'
Clarence's eyes grew wide upon the realization. He didn't specifically mention mana sense to the system when he wanted an item to hide him from that specifically, because he thought it was obvious.