What are the first two dangers the narrator faces in "The Pit and the Pendulum"?

The first two dangers faced by the narrator of this story would be the pit and the pendulum, so the story is aptly named.

When he first wakes up in his pitch black cell, he starts trying to measure its size by trailing his hands along the wall and measuring by pace. This in and of itself is not the dangerous part; it is when the narrator paces more into the center of the room, trying to figure things out, that he comes close to losing his life. He trips and falls, and he realizes that his head is not touching anything, meaning that he tripped close enough to the pit that his head dangled over the edge.

The next danger is after he is drugged by his food and he wakes up tied down to the floor, and he can see the pendulum slowly descending as it swings back and forth. Luckily, he is clever, and he spreads what is left of his food onto the ropes holding him down, which baits the rats into chewing through the ropes and setting him free just before the pendulum reaches him.