In the first place, we should not think of that great depth.

If a man fell down any one of the deep shafts in our silver mines, he would be as thoroughly deprived of life as if he should fall down my shaft.

But to fall down mine--and I want you to consider this, Margaret, and thoroughly understand it--would be almost impossible.

I have planned out all the machinery and appliances which would be necessary, and I want to describe them to you, and then, I am sure, you will see for yourself that the element of danger is more fully eliminated than if I should row you on the lake in a little boat." She sat quiet, still pale, still listening, her eyes fixed upon him.
"I have devised a car," he said, "in which I can sit comfortably and smoke my cigar while I make the descent.

This, at the easy and steady rate at which my engines would move, would occupy less than three hours.
I could go a good deal faster if I wanted to, but this would be fast enough.