only one-hundredth of the entire nebula were condensed on the earth, the
whole mass of the nebula would not need to exceed one three-hundredth of
the weight of the earth, or a quarter that of the moon--and nobody here
will be bold enough to say that the approach of a mass no greater than
that would be likely to be discovered through its attraction when it was
three hundred million miles away."

Several of the astronomers present shook their heads at this, and
Professor Pludder irritably declared that it was absurd.

"The attraction would be noticeable when it was a thousand millions of
miles away," he continued.

"Yes, 'noticeable' I admit," replied Professor Moses, "but all the same
you wouldn't notice it, because you wouldn't be looking for it unless
the nebula were visible first, and even then it would require months of
observation to detect the effects. And how are you going to get around
those bulletins? The thing is beginning to be visible now, and I'll bet
that if, from this time on, you study carefully the planetary motions,
you will find evidence of the disturbance becoming stronger and
stronger. Versal has pointed out that very thing, and calculated the
perturbations. This thing has come like a thief in the night."

"You'd better hurry up and secure a place in the ark," said Professor
Pludder sarcastically.

"I don't know but I shall, if I can get one," returned Professor Moses.
"You may not think this is such a laughing matter a few months hence."

"I'm surprised," pursued the president, "that a man of your scientific