Edmond Halley publishes “Astronomiae cometicae synopsis” and demonstrates that the comets of 1531, 1607, and 1682 are the same comet, which today bears his name. He calculates its orbit and predicts its return around 1757 or 1758. In reality, Jupiter and Saturn will alter its orbit, delaying its return. Clairaut will calculate the perturbation, estimating its perihelion as April 13, 1759. This will occur on March 13, 1759.
