Laplace that this invention was the
means of doubling the life of an astronomer, besides enabling him to
avoid errors and the tediousness associated with long and abstruse
calculations.

THOMAS HARRIOT, an eminent mathematician, and an assiduous astronomer,
made some valuable observations of the comet of 1607. He was one of the
earliest observers who made use of the telescope, and it was claimed on
his behalf that he discovered Jupiter's satellites, and the spots on the
Sun, independently of Galileo. Other astronomers have been desirous of
sharing this honour, but it has been conclusively proved that Galileo
was the first who made those discoveries.

The investigations of Norwood and Gilbert, the mechanical genius of
Hooke, and the patient researches of Flamsteed--the first Astronomer
Royal--were of much value in perfecting many details associated with the
study of astronomy.

The Royal Observatory at Greenwich was founded in 1675. The building was
erected under a warrant from Charles II. It announces the desire of the
Sovereign to build a small observatory in the park at Greenwich, 'in
order to the finding out of the longitude for perfecting the art of
navigation and astronomy.' This action on the part of the King may be
regarded as the first public acknowledgment of the usefulness of
astronomy for national purposes.

Since its erection, the observatory has been presided over by a
succession of talented men, who have raised it to a position of eminence
and usefulness unsurpassed by any similar institution in this or any
other country. The well-known names of Flamsteed, Halley, Bradley, and
Airy, testify to the valuable services rendered by those past directors
of the Greenwich Observatory in the cause of astronomical science.

If we take a general survey of the science of astronomy as it existed
from 1608 to 1674--a period that embraced the time in which Milton
lived--we shall find that it was still compassed by ignorance,
superstition, and mystery. Astrology was zealously cultivated; most
persons of rank and position had their nativity or horoscope cast, and
the belief in the ruling of the planets, and their influence on human
and terrestrial affairs, was through long usage firmly established in
the public mind. Indeed, at this time, astronomy was regarded as a
handmaid to astrology; for, with the aid of astronomical calculation,
the professors of this occult science were enabled to predict the
positions of the