But ? Overhead.

He didn't flinch.

The trick, he realized, wasn't to push the rod up into the gap. It was to hold a tight arc. So tight the flux created a surface tension bubble, a little glass ceiling that held the molten metal in place against the pull of the earth.

The 4G was the monster under the bridge.

Old Lin walked in the next morning, saw the sample, and said nothing. He just picked up his stamp—a heavy, brass thing—and slammed it onto Marco's test coupon.

Marco didn't understand. He spent the night before his fourth attempt in the shop alone. He set up the 6-inch schedule 80 pipe in the overhead position. He adjusted his hood to a #10 shade. He cranked the Miller machine to 92 amps—hotter than he was comfortable with.