ous historians and chroniclers of that day agree that this event was announced by a comet, which proves to have been this one of Halley. To eclipses of the moon, April the second and September the twenty-sixth of this year, assist in fixing the date securely. The second of these eclipses is charged to the account of the comet itself. The return in 1066 has received much attention on account of its supposed connection with invasion of England by William, the Norman, and with the overthrow of Harold at Hastings.
By 1456 something more like scientific activity had begun. It was indeed nearly one hundred years before the publication of the immortal work of Copernicus, and astronomical observers were few and far between, particularly in Europe. In recent times a series of observations has been brought to light, made by Toscanelli in Florence. The discovery was made by Celoria, in 1885, and, as may be supposed, it is a most welcome addition to our data for fixing the exact circumstances of this appearance. Perhaps never before or after has a comet caused so much consternation as upon this occasion. Three years before, the Turks under Mahomet the second had taken Constantinople and their armies were pushing their conquests to the west. Many were apprehensive of the complete subjugation of Europe. Then a brilliant comet appeared, the precursor, as was supposed, of further calamities, and a universal panic seems to have taken possession of high and low alike. Who wonders if the pope ordered the church bells to be rung everywhere at noon, and that all should then engage in prayer for the protection against the Turks and the comet?
1531 is one of the dates used Halley in fixing the character of the orbit, the other two being 1607 and 1682. This appearance is known as the comet of Apian, that is, Petrus Apianus, alias Peter Bienewitz, court astronomer of Charles V., and of Ferdinand I. His observations
