Give an account of the astronomers cave in the flying land of Laputa?

The astronomer's cave was situated at a depth of hundred yards below the upper adamant. There were twenty lamps in the cave that burned continuously to light up every part of the cave. There were several astronomical instruments, quadrants, sextants and telescopes. The major attraction was the lodestone, which was a magnet that was responsible for the movement of the island in the air.