“You’ve shown that the probe can see through all kinds of murk, and to a not inconsiderable depth. But two miles deep this tank is not. How do you know that the significantly increased signal distance won’t simply refract your imagery beyond recognition?”

“Well, General,” said Madeline, turning briefly to Neal to flash a smile at him, “that is an important question, and one we have battled with. We did come up with an experiment to test it, but it is a little … unconventional. If I may suggest we take a brief lunch break while we set it up, and then I hope we will be able to set your mind at ease.”

* * *

As the group filed back in from their foray to the Institute’s cafeteria, they were directed to a second part of the vast hangar that housed the various experiments the Institute was working on at that time. Though smaller in overall size than the main hangar, this room still ran the entire length of the back of the building. It contained only one structure. Originally designed for warping or “eccentricity” tests on the driveshafts of naval ships and cruise liners, the room held a single tube, five feet wide and 450 feet long. At any point along its length the hinged top cover could be opened to allow access, and the entire tube was mounted on rollers so that it could be rotated through 100o to allow for the removal of the test shafts onto railings that ran the length of the hangar.

The tube was empty now, its top covers closed, and in place of the stress engines normally placed at each end there were covers fitted to block the gaps. At one end a duplicate of the probe from the tank was secured into this cover, facing down the length of the tube. At the other end, they had arranged iron pieces on the inside of the cover, similar to the ones used at the bottom of the pool.

There were no seats here, so the review committee filed in and formed a line along the side wall. General Pickler was the first to speak: “Well, I guess I’m curious how this will help us anymore than the tank. How much longer is this, exactly?”

“Well, General,” started Madeline, “the tube is actually only 150 feet longer than the tank is deep, but it is not filled with water.”

“Well, what is it filled with?” he said to a mix of consternation and curiosity from the rest of the committee.

“Well, General, it isn’t filled with anything, not yet, at least.” She smiled at him without a hint of concern or patronizing tone, “To simulate two miles of depth we needed a substance much denser than water, but with some of the same properties.

“We can thank Captain Hawkson for his recommending something he had worked with in his navy days, which refracts at a degree twenty-three times greater than water.”