The three looked at each other significantly.  Clearly, the thing that had just happened argued a great lapse of time since the user of that desk officiated in that enclosure.  It looked as though Smith’s guess of “weeks, perhaps months,” would have to be changed to years, perhaps centuries.

“Feel all right?” asked the geologist.  Jackson and Smith made affirmative noises; and again they stepped out, this time walking in the aisle along the outer wall.  They could see their sky-car plainly through the ovals.

Here the machinery could be examined more closely.  They resembled automatic testing scales, said Smith; such as is used in weighing complicated metal products after finishing and assembling.  Moreover, they seemed to be connected, the one to the other, with a series of endless belts, which Smith thought indicated automatic production.  To all appearances, the dust-covered apparatus stood just as it had been left when operations ceased, an unguessable length of time before.

Smith showed no desire to touch the things now.  Seeing this, the geologist deliberately reached out and scraped the dust from the nearest machine; and to the vast relief of all three, no damage was done.  The dust fell straight to the floor, exposing a brilliantly polished streak of greenish-white metal.

Van Emmon made another tentative brush or so at other points, with the same result.  Clean, untarnished metal lay beneath all that dust.  Clearly it was some non-conducting alloy; whatever it was, it had successfully resisted the action of the elements all the while that such presumably wooden articles as the desk and railing had been steadily rotting.

Emboldened, Smith clambered up on the frame of one of the machines.  He examined it closely as to its cams, clutches, gearing, and other details significant enough to his mechanical training.  He noted their adjustments, scrutinized the conveying apparatus, and came back carrying a cylindrical object which he had removed from an automatic chuck.

“This is what they were making,” he remarked, trying to conceal his excitement.  The others brushed the dust from the thing, a huge piece of metal which would have been too much for their strength on the earth.  Instantly they identified it.

It was a cannon shell.

Again Van Emmon led the way.  They took a reassuring glance out the window at the familiar cube, then passed along the aisle toward the farther corner.  As they neared it they saw that it contained a small enclosure of heavy metal scrollwork, within which stood a triangular elevator.

The men examined it as closely as possible, noting especially the extremely low stool which stood upon its platform.  The same unerodable metal seemed to have been used throughout the whole affair.

After a careful scrutiny of the two levers which appeared to control the thing—­“I’m going to try it out,” announced Smith, well knowing that the others would have to go with him if they kept the telephones intact.  They protested that the thing was not safe; Smith replied that they had seen no stairway, or anything corresponding to one.  “If this lift is made of that alloy,” admiringly, “then it’s safe.”  But Jackson managed to talk him out of it.