But even as he spoke, and before he had moved two feet, that catastrophe seemed at least to have begun. The prop gave way: the light at the entrance was at once blotted out; the air was filled with terrifying roaring echoes. There followed a succession of crashes, the rolling of rocks over each other, the grinding slide of avalanches great and small. We could scarcely breathe for the dust. Our danger was that now the thing was started it would not stop: that the antique and inadequate supports would all give way, one bringing down the other in succession until we were buried. Would the forces of equilibrium establish themselves through the successive slight resistances of these rotted, worm-eaten old timbers before the constricted space in which we crouched should be entirely eaten away?
After the first great crash there ensued a moment's hesitation. Then a second span succumbed. There followed a series of minor chutes with short intervening silences. At last so long an interval of calm ensued that we plucked up courage to believe it all over. A single stone rolled a few feet and hit the rock floor with a bang. Then, immediately after, the first-deafening thunder was repeated as evidently another span gave way. It sounded as though the whole mountain had moved. I was almost afraid to stretch out my hand for fear it would encounter the wall of débris. The roar ceased as abruptly as it had begun. Followed then a long silence. Then a little cascading tinkle of shale. And another dead silence.
"I believe it's over," ventured Miss Emory, after a long time.
"I'm going to find out how bad it is," I asserted.
I moved forward cautiously, my arms extended before me, feeling my way with my feet. Foot after foot I went, encountering nothing but the props. Expecting as I did to meet an obstruction within a few paces at most, I soon lost my sense of distance; after a few moments it seemed to me that I must have gone much farther than the original length of the tunnel. At last I stumbled over a fragment, and so found my fingers against a rough mass of débris.
"Why, this is fine!" I cried to the others, "I don't believe more than a span or so has gone!"
I struck one of my few remaining matches to make sure. While of course I had no very accurate mental image of the original state of things, still it seemed to me there was an awful lot of tunnel left. As the whole significance of our situation came to me, I laughed aloud.
"Well," said I, cheerfully, "they couldn't have done us a better favour! It's a half hour's job to dig us out, and in the meantime we are safe as a covered bridge. We don't even have to keep watch."
"Provided Brower gets through," the girl reminded us.
"He'll get through," assented Tim, positively. "There's nothing on four legs can catch that Morgan stallion."