The conversion of raw air-powered power into razor-sharp battlefield artillery needed mathematics, not fortune-telling.
In the dispatch office of the Grey Crag Central Station, Giles Croft sat at his broad drafting board beneath the yellow light of two high-pressure gas lamps.
His ten-inch celluloid-faced Mannheim slide rule moved between his fingers with steady, rhythmic care. Beside him stood Toby Karr and apprentice Marta, carefully transcribing rows of calculated figures onto heavy, varnished cardboard firing cards.
“Artillery flight path isn’t a straight line,” Giles explained. He pointed with the hairline runner of his slide rule.
“It’s a parabola modified by wind-cutting drag and sky thickness. The level distance traveled equals the first speed squared multiplied by the sine of two theta, divided by gravity gaining speed.”
Toby inked a neat column on the card: ELEV 52 DEG / bone-crushing pressure / 1,480 YARDS.
“And the wind, Lord Giles?” Toby asked. “The mountain wind shifts across Granite Gap like an angry river.”
“Wind drift is a cross-axis vector,” Giles said.
