"We carried with us a small scaling-ladder and up this I went. The
bosses were apparently nothing more than chiseled curvatures in the
stone. I laid my hand on the one I was examining, and drew it back
sharply. In my palm, at the base of my thumb, I had felt the same
shock that I had in touching the slab below. I put my hand back. The
impression came from a spot not more than an inch wide. I went
carefully over the entire convexity, and six times more the chill ran
through my arm. There were seven circles an inch wide in the curved
place, each of which communicated the precise sensation I have
described. The convexity on the opposite side of the slab gave exactly
the same results. But no amount of touching or of pressing these spots
singly or in any combination gave the slightest promise of motion to
the slab itself.

"'And yet--they're what open it,' said Stanton positively.

"'Why do you say that?' I asked.

"'I--don't know,' he answered hesitatingly. 'But something tells me
so. Throck,' he went on half earnestly, half laughingly, 'the purely
scientific part of me is fighting the purely human part of me. The
scientific part is urging me to find some way to get that slab either
down or open. The human part is just as strongly urging me to do
nothing of the sort and get away while I can!'

"He laughed again--shamefacedly.

"'Which shall it be?' he asked--and I thought that in his tone the
human side of him was ascendant.