Chapter 9
SADY SPREAD the map out over the camp table.
The automated barygraphs hadn’t lied. He had half-hoped that the devices, such as the one that stood at the base of the telegraph pole in the forest clearing, had malfunctioned, and that the massive dip in air pressure some instruments had recorded yesterday was the result of a mere error. But the protective glass was intact, and so was the tiny bellows that contracted and expanded with the air pressure, and the thin needle, precision-mounted on a rod of crystal, which didn’t expand much with heat. The bellows pushed or pulled one end of the needle, the crystal acted like a see-saw and the other, longer, end of the needle went up or down, touching thin copper wires set at intervals. Each time the needle passed such a wire, it would s
