Nearer the gods no mortal may approach.

Aristotle's opinion... that comets were nothing else than sublunary vapors or airy meteors... prevailed so far amongst the Greeks, that this sublimest part of astronomy lay altogether neglected since none could think it worthwhile to observe, and to give an account of the wandering and uncertain paths of vapours floating in the Ether.

Scarce any problem will appear more hard and difficult, than that of determining the distance of the Sun from the Earth very near the truth: but even this... will without much labour be effected.

This sight... is by far the noblest astronomy affords.

In the year 1456 ... a Comet was seen passing Retrograde between the Earth and the sun... Hence I dare venture to foretell, that it will return again in the year 1758.