On January 1, 1801 Father Giuseppe
Piazzi was observing for a new star catalogue a
collection of the precise location of all stars visible
from the island of Sicily. He was using a telescope
with a focal length of about 1.5 meters.

The
telescope was mounted on a tripod and the observer
stood on a platform. The platform was about 1.5 meters
above the ground. The observer was looking