Sure enough, though, the thing lifted. Up it bobbed, like a metal dirigible with agonizing gas pains, shrieking louder by the second. When the plaster started to trickle and flake from the walls, and the fillings in my teeth rose to a temperature just short of incandescence, I decided it was time to cancel this phase of the experiment, and, with very little regret, I flung a blanket-like canvas tarpaulin up and over the ascending machine before it started using its helices to screw into the ceiling. The cones bit into the tarpaulin, tangled, jammed, and the machine--mercifully noiseless, now--crashed back onto the scale, and lost a lot of symmetry and a couple of rivets. "What's Plan C?" I said to Artie. "_Quiet!_" he said, either because I'd interrupted his thinking or because that was our next goal. * * * * * The next four days were spent in the arduous and quite tricky business of reaming acoustically spaced holes along the flanges. Artie's theory was that if we simply ("simply" was his word, not mine) fixed it so that the sound made by each flange (anything whirly with a hole or two in it is bound to make a calculated noise) was of the proper number of vibrations to intermesh with the compression/rarefaction phases of the sounds made by the other flanges, a veritable sphere of silence would be thereby created, since there'd be no room for any sound waves to pass through the already crowded atmosphere about the machine. "It'll make less noise than a mouse in sneakers drooling on a blotter!" enthused Artie, when I had it rigged again, and ready to go. "Still," I said uncertainly, "whether we _hear_ it or not, all that soundwave-energy has to do _something_, Artie. If it turns ultrasonic, we may suddenly find ourselves in a showerbath of free electrons and even _worse_ subatomic particles from disrupted air molecules. Or the lab might turn molten on us. Or--" "Oh, turn it _on_, Burt!" said Artie. "That's just a chance we have to take." "Don't see why we _have_ to take it...." I groused, but I'm as curious as the next man, so I turned it on. (I could have arranged to do it by remote control, except for two pressing deterrents: One--At a remote point of control, I wouldn't be able to watch what, if anything, the machine did, and Two--Who knows where the _safe_ spot is where soundwaves are concerned? With some sonic forces, you're safer the _nearer_ you get to the source.) So, like I said, I turned it on.