"There's a big drop in efficiency compared to when we left the Plutonian Lens." "How much?" "Not too much. But it's getting progressively worse." "Y'don't suppose we've hit upon some saturation factor in the secondary drive?" "I'm not saying. What do we know about it? What does it work on?" "Glibly speaking, it works on the inherent qualities of space. We wrap ourselves up in a space-warp of sorts, and then shoot out a couple of hooks that catch on to the gravitic-propagational continuum that permits the planetary masses to exert Newton's Law of Universal Gravitation. It has been called 'sub-ether' but that is like multiplying with unreal numbers. After all, the 'ether' has never been defined, isolated, explained, or held in one hand. If the prime 'ether' has never been satisfactorily established, we shouldn't go on building our houses on a foundation that doesn't have any sound basis." "Both electronic and gravitic spectra must rely upon something for propagation," objected McBride. "For lack of taking it apart, brick by brick, and feeling each stone, let's continue to call them 'ether' and 'sub-ether.'" "O.K., sport. But to get back to the drive. Have we got a saturation point? Or some sort of gravitic fatigue? Either of these would be indicated by a gradual decrease in efficiency." "Larry, set up a sigma recorder and let's see if we can check the curve of inefficiency. It's getting worse, you say?" "Apparently. I didn't notice it before. But it is quite apparent now. Must be non-linear, because if this falling-off had been linear, I would have noticed it long before this. An increasing curve would not be noticeable until a sufficient interval had been passed for it to become evident. Yeah, I'll slap a sigma recorder on him and see what makes." "Meanwhile, let's get busy with the detectors." The counters clicked for a few minutes, and McBride finally reported that Telfu was no higher than Terra in radioactivity. Hammond established the intrinsic electronic charge on Telfu as being only a few million volts negative with respect to Terra. "Not enough to worry about," he said. "The first touch with the stratosphere layers will take care of that without a glimmer. Wouldn't dare without an atmosphere, but we have plenty of air to cushion the charge and let it leak off in the upper layers where it is ionized by Sirius' radiations. What's with the gravitics?" "Bit of something in the electrogravitic. Can't place it. Not enough to worry about." "What is it like?" "Well, it is not E-grav radiation. It's a sort of dip, or valley, in the radiation-pattern of this part of space. A place where the normal density of E-grav is less." "How much?" "You tell me. The free-running gravitons are never high enough to do more than flicker the finest instrument. The threshold is way, way, way, way down in the mud. So here's a place where we have less." "Sort of like having nothing and wanting to share it with someone?"