The observatory predates the invention of refracting telescopes. It was used to determine the position and movement of stars and planets, not to observe them. T

The observatory predates the invention of refracting telescopes. It was used to determine the position and movement of stars and planets, not to observe them. The "quadrant" is a device to accurately measure the angle of an observation: https://en.m.wikipedia.org/wiki/Quadrant_(instrument) https://en.m.wikipedia.org/wiki/Quadrant_(instrument)