There, the astronomer Jean Picard devised an impressively complicated method of triangulation involving quadrants, pendulum clocks, zenith sectors, and telescopes for observing the motions of the moons of Jupiter.

在那里，天文学家让·皮卡尔发明了一种极其复杂的三角测绘法，用上了扇形板、摆钟、天顶象限仪和天文望远镜用来观察土星卫星的运动。