In 1283, say the annals of Dunstable, "We sold our slave by birth, William Pike, with all his family, and received one mark from the buyer." Men must have been cheaper than horses. In 1340, gunpowder and guns were first invented by Swartz, a monk of Cologne. In 1346, Edward III. had four pieces of cannon, which contributed to gain him the battle of Cressy. Bombs and mortars were invented about this time. In 1386, the magnificent castle of Windsor was built by Edward III. and his method of conducting the work may serve as a specimen of the condition of the people in that age. Instead of engaging workmen by contracts or wages, he assessed every county in England to send him a certain number of masons, tilers, and carpenters, as if he had been levying an army. In 1654, the air pump was invented by Otto Guericke, a German. 1406, B.C. Iron first discovered by burning the woods on Mount Ida, in Greece. 720, B.C. The first lunar eclipse on record. Anaximander, the disciple of Thales, invented maps and globes; born about 610 B.C. 894, B.C. Gold and silver money first coined at Argos, in Greece. 274, A.D. Silk first imported from India. 664, A.D. Glass first invented in England by O. Benalt, a monk. 1284, A.D. The Alphonsine Astronomical Tables constructed, under the patronage of Alphonso X. of Laon and Castile. 1337, A.D. The first comet described with astronomical precision. The first diving bell we read of was a very large kettle suspended by ropes with the mouth downwards, and planks fixed in the middle of its concavity. Two Greeks at Toledo in 1583, made an experiment with it before Charles V. They descended in it with a lighted candle to a great depth. The Odyssey was written upon the skin of a serpent. Formerly pennies were marked with a double cross and crease, so that it might easily be broken into two or four parts. HALBERT H. * * * * * THE SKETCH-BOOK * * * * * SKETCH OF THE BATTLE OF ALGIERS. _By an officer engaged._ The Leander, fitted for the flag of Rear-Admiral Milne, was at Spithead, in June, 1816, when Lord Exmouth arrived with a squadron from the Mediterranean, where a dispute had arisen between the Dey of Algiers and his lordship, in consequence of a massacre that took place at Bona, on the persons of foreigners, then under the protection of the British flag.