Self-illumined by the heat evolved in striking the various layers of the earth’s atmosphere, it became sufficiently bright to be first seen when seventy miles above the surface of the earth. It was within forty miles of touching us at the time it was over the Hudson River, when the great heat acquired by its rapid transit caused it to burst into two masses, which—like Biela’s comet—continued to pursue separate courses, side by side, until they were lost to view in their ascending flight, being last seen from the deck of a vessel off the island of Nantucket. No part of the fire-ball struck the earth. Its orbit was an hyperbola, a curve not often found in nature, such that it can never come near us again unless, by the superior attraction of some celestial body, its course may be changed, and a new orbit result. VI. ASTRONOMICAL OBSERVATORIES. The Royal Observatory, at Greenwich, England, was founded by Charles the Second in 1675. Its main purpose was to extend astronomical knowledge, so that navigators might better find the position of their ships at sea. This institution retains its prominence. All the longitudes on our maps are reckoned from it, and Greenwich time is used on every ship that traverses the ocean. The “Nautical Almanac,” issued by the Observatory, was an indispensable part of the outfit of every sea captain until, in 1852, the United States provided its own American Ephemeris, a collection of tables of the motions and places of the sun, moon, and planets for every day and hour, and occultations of the stars, with rules for calculating longitude and the like. Many valuable observations of the transit of Venus in 1769 were made at points near Philadelphia; but almost seventy years ensued before America witnessed the erection of any permanent buildings devoted to the purposes of this science. President John Quincy Adams, who was highly versed in science, and held the position of president of the American Academy of Arts and Sciences in Boston for twenty years, often urged this matter on the attention of Congress, but without success. President Thomas Jefferson, who was also a man of no small scientific information, as evidenced in his keeping a systematic weather record at his home in Monticello, Virginia, proposed an elaborate survey of the national coast. This was authorized by Congress in 1807. In the year 1832, in reviving an act for the continuance of the Coast Survey, Congress was careful to append the proviso “that nothing in the act should be construed to authorize the erection or maintenance of a permanent astronomical observatory.”