unreasonable those manifestations we first got were!"
"But can't you get any control at all?"
“Very little. Anyway, if I could get inertialess conditions at will, I'd be afraid of them. They'd make chemical reactions impossible in all probability—and life is chemical. Two atoms must come into more or less violent contact before a union takes place, and cannot if they have neither momentum nor inertia."
"Anyway—why worry. I can't do it, because I can't control this thing. And we have the extra-space drive."
"How does that darned thing work? Can't you drop the math, and tell me about it?"
Kendall smiled. "Not too readily. Remember first, as to the driving system, that it works on the fabric of space. Space is, in the physical sense, a fabric woven of the threads of lines of force from every body in the universe, made up of fields and forces. It is elastic, and can transmit strains. But anything that can transmit strains, can be strained against. With the tremendous field intensities available by the material engines, I can get such fields as will 'dig their toes' into space and push.
"That's the drive itself. It is accelerationless, because it enfolds us, and acts equally on every atom of us. By maintaining in addition a slight artificial gravity—thanks also to the intensity of those material engine fields—we can be comfortable, while we accelerate at tremendous rates."
"That is, I think, at least allied to the Stranger's system. For the high speed drive, I do in fact use the Uncertainty. I can control it in a certain sense by determining its powers, and the limits of uncertainty, whether First, Second, Third or Fourth Degree. It advances in jumps—but on a finer plotting of the curve, you can see that each jump represents a vast series of smaller jumps. That is there is Class A, B, C, D, and so forth Uncertainty of the First Degree. Now Class A First Degree Uncertainty involves only the deepest, broadest principles. Only they break down. One of these is the law of the speed of light.
"I'm sure that isn't the system the Strangers use, but I'm also sure there's no limit to the speed we can get."
"Doesn't that wreck your drive system?"
"No, because gravity and the fields I use in driving are First Degree Uncertainties of the higher classes.
"But at any rate, it will work. And—I suspect you came to say you were ready to go."
"I did," nodded McLaurin.
"Still stick to your original plan?"
McLaurin nodded. "I think it's best. You follow those fellows back to their system in the 'S Doradus' and I'll stay here in the 'Cephid' to protect the system. They may need some time to get out of the place here. And remember, we ought to be as decent as they were. They didn't bother the transports leaving Jupiter when they came in, only attacked the warships. We're bound to do the same, but we'll have to keep a watch on them none the less. So you go on ahead."
They started down the corridor, and came presently to the huge locks where the "S Doradus" and the "Cephid" were berthed. The super-ships lay cold and grey now, men swarming in and out with last-minute supplies. Air, water, spare parts, bedding and personal equipment. Douglass, Cole, and most of the laboratory staff would go with Kendall when he
