Chapter XXIV. The Hidden City - Page 2

"Bless my--" began Mr. Damon, but he got no further, for a mighty gust of wind swept out of the tunnel, and blew off his hat. That gust was but a gentle breeze, though, compared to what followed. For there came such a rush of air that it almost blew over those standing near the opening of the great shaft driven under the mountain. There was a roar as of Niagara, a howling as in the Cave of the Winds, and they all bent to the blast.

Then followed a dull, rumbling roar, not as loud as might have been expected, but awful in its intensity. Deep down under the very foundations of the earth it seemed to rumble.

"Run! Run back!" cried Tom Swift. "There's a back-draft and the powder gas is poisonous. Stoop down and run back!"

They understood what he meant. The vapor from the powder was deadly if breathed in a confined space. Even in the open it gave one a terrible headache. And Tom could see floating out of the tunnel the first wisps of smoke from the fired explosive. It was lighter than air, and would rise. Hence the necessity, as in a smoke-filled room, of keeping low down where the air is purer.

They all rushed back, stooping low. Mr. Damon stumbled and fell, but Koku picked him up and, tucking him under one arm, as he might have done a child, the giant followed Tom to a place of safety.

"Well, Tom, it went off all right," said Mr. Job Titus, as they stood among the shacks of the workmen and watched the smoke pouring out of the tunnel mouth.

"Yes, it went off. But did it do the work? That's what we've got to find out."

They waited impatiently for the deadly vapor to clear out of the tunnel. It was more than an hour before they dared venture in, and then it was with smarting eyes and puckered throats. But the atmosphere was quickly clearing.

"Switch on the lights," cried Tom to Tim, for the illuminating current had been cut off when the blast was fired. "Let's see what we've brought down."

Following the eager young inventor came the contractors, some of the white workers, Mr. Damon and Professor Bumper. The little scientist said he would like to see the effect of the big blast.

Along they stumbled over pieces of rock, large and small.

"Some force to it," observed Job Titus, as he observed pieces of rock close to the mouth of the tunnel. "If it only exerted the force the other way, against the face of the rock, as well as back this way, we'll be all right."

"The greater force was in the opposite direction," Tom said.

A big search-light had been got ready to flash on the place where the blast had been set off. This was to enable them to see how much rock had been torn away. And, as they reached the place where the flint-like wall had been, they saw a strange sight.

"Bless my strawberry