Ren put it together speedily, placing it in the wall clamps designed to hold it. The glass itself was graduated with the scale of gravity strength. The cylindrical weight at the free end of the spring had a line on it that would coincide with the proper reading.
In practice it vibrated up and down so that it had to be read by estimation of the half-way point of the up and down motion.
Ren and Ford watched the red weight with its black line. It moved slowly and uniformly from the bottom to the top of the scale, from a full g to ten thousandth of a g, and back down again.
Meanwhile the gravity potentiometer (gravy board) was changing its reading constantly and erratically.
Ford licked his lips nervously and said, "Don't know what the old man'll say about this, but it looks like all we can say is that the thing has gravity."
"Why not call him and let him see for himself?" Ren asked.
Ford looked out the viewport at the round object in the distance and shook his head.
"I've got a hunch he knows it already," he said slowly. "The ship is probably on a nonsense track and the automatic tracker is either trying to find out what the law of gravity is, or is exploring for clues to light aberration. One gets you ten he'll give me a buzz in another minute."
He was right. The phone rang almost at once. It was Hugh Dunnam himself, asking for the gravy reading.
"You'll have to see it to believe it," Ford Gratrick said over the phone. "The manual swing is uniform over the whole range. The gravy board can't make up its mind where to settle at. It tries this and that reading."