Byrgius

It was south of the Byrgius crater, not west of Legendre crater.

Using images from an amateur astronomer, Christian Fröschlin, Mr. Cowart determined that the flash took place somewhere in the lunar highlands, south of Byrgius crater.

The Kepler, Aristarchus, and Copernicus systems, though of much smaller extent, are very noteworthy from the crossing and apparent interference of the rays; while those near Byrgius, round Aristarchus, and the rays from Proclus, are equally remarkable.

BYRGIUS.—A very irregular enclosure, about 40 miles in diameter, between Cavendish and the E. limb, with a lofty and discontinuous border, rising at one point on the E. to a height of 7000 feet above the floor.

The border is broken on the E. by a crater, and on the W. by the well-known crater Byrgius A, from which a number of bright streaks radiate, mostly towards the E. One on the W. extends to Cavendish, and another to Mersenius, traversing the ring-plain Cavendish C. North-east of Byrgius there is a mountain arm which includes a peak 13,000 feet in height.