OBSERVATOIRE, Fr. See [Observatory].
OBSERVATORY, a building, public or private, which is erected and provided with all sorts of instruments, proper for astronomical observations, &c. The most noted observatories in Europe, are:
1. That of Tycho Brahe, a nobleman of Denmark, at Uraineberg, in the island of Wern, between the coasts of Schonen and Zealand, in the Baltic.
2. The observatory at Paris, which was erected by Louis XIV. This building stands in the Fauxbourg St. Germain, and is so constructed as to answer the four cardinal points of the world, east, west, north and south. The foundation is laid 80 feet below the ground, and the edifice carried as much above it. It contains three stories in height, and has a terrace at top, from whence the whole horizon appears flat. The stair-case of this observatory deserves notice, from the singularity of its construction, being in the form of a screw, and so contrived, that from the bottom there is a full sight of the stars that pass the zenith of this place.
3. The royal observatory at Greenwich, in England, which was founded by Charles the second.
4. The observatory at Pekin in China, which was erected by the late emperor, at the intercession of the Jesuits.
To OBSERVE, to watch closely, &c. Hence, to observe the motions of an enemy, is to keep a good look out by means of small corps of armed men, or of intelligent and steady spies or scouts, and to be constantly in possession of his different movements. No man can be said to have the talents of an able general, who neglects to observe his enemy in all directions; for if it be his intention to attack, you may thwart him by previous manœuvres; and if you are liable to be attacked yourself, you may assume the best possible position, and prevent surprise, &c.
OBSESSION. The act of besieging.
OBSIDIONAL, belonging to a siege.
Obsidional Crown, (couronne obsidionale, Fr.) a crown so called among the ancient Romans, which was bestowed upon a governor or general, who by his skill and exertions, either held out, or caused the siege to be raised of any town belonging to the republic. It was made from the grass which grew upon the spot, and was therefore called gramineus, from the Latin word gramen, signifying grass.