Aristotle did not use any instruments to measure the Earth. He was a philosopher and scientist who lived in ancient Greece, centuries before the development of modern scientific instruments. He relied on observations, logic, and deductions to formulate his theories about the Earth and the universe.

While Aristotle did have some ideas about the size and shape of the Earth, he didn't have the tools or knowledge to actually measure it. The first accurate measurement of the Earth's circumference was made by Eratosthenes of Cyrene in the 3rd century BC, using a method based on the angle of the sun at two different locations.