ties of enameled glass are strikingly shown in Prince Rupert's drops and the Bologna vial.
The former are prepared by allowing melted glass to drop into water, where the drops which are not broken by contact with the water form irregularly elongated globular bodies tapering to a tail at one extremity.
These will bear a considerable blow on the thick end without breaking, but if a small piece be snapped off the tail the whole immediately falls into powder, emitting a cracking sound.
The Bologna vial is a rude flask of some three or four inches in length by about one in diameter, and from 1/10 to 1/8 of an inch in thickness.
If a leaden bullet be dropped into it from a height of three or four feet, or it be struck a smart blow on the outside with a stick, it will not break, but the dropping of a grain of sand or a small sharp fragment of flint into it will cause it to crack and fall to pieces.
Upon the proper annealing of glass much of its utility for many purposes entirely d
r cutwaters, and the raft — for such it is — is sometimes from 20 to 25 feet long and 2 1/2 to 3 1/2 feet wide.
They land and push off through surfs, on the Madras coast, which would swamp even the country boats.
In moderate weather they carry matting sails by means of an outrigger.
They may be seen on the west coast of South America many miles out at sea, carrying Indians employed in fishing.
b. The incendiary rafts prepared by Sir Sidney Smith for destroying the French flotilla at Bologne, 1804, were called catamarans.
The flotilla was constructed for the invasion of England by Bonaparte; the floating carcasses were a failure; but for his own reasons the general broke up his camp and transported his troops to the Rhine.
The capitulation of Ulm and the battle of Austerlitz soon followed.
A receptacle for the catamenia.
An ancient engine for hurling stones or darts.
It is usually represented as a cross-bow on a la
ut all we have; rather look for the charlatans among those who pretend to have penetrated the arcana.
Among the galvanic appliances may be cited bands, belts, chains, combs, rings, soles, spectacles, etc.
Galvani, of Bologna, first observed the motion of the muscles of a frog under dissection, when the latter, lying upon a copper plate, were touched by a steel scalpel, exciting an electric current.
He pursued the subject by specific experiments.
Volta, of Como, reervation made at Marseilles by Pytheas in the time of Alexander the Great showed that the gnomon at that place was as the meridian shadow at the summer solstice, as 213 1/2 to 600.
Cassini's celebrated gnomon in the Church of St. Petronius at Bologna was eighty-three French feet in hight.
（Mining.) An excavated space from which the ore has been removed.
It is sometimes made the receptacle for the deads and attle of the mine to avoid sending them up to the surface, and to suppo<
A drying-chamber for cloths or paper, starch, etc.
A name applied to amalgam gilding, in which the mercury is driven off by heat.
1. (Pottery.) A room where strong heat completes the drying of green ware, previously to placing in seggars and firing in a kiln.
2. (Horticulture.) A plant-house where a relatively high artificial temperature is maintained in order to facilitate vegetable growth.
The botanic gardens of Pisa, Padna, and Bologna, established from 1544 to 1568, did not contain hot-houses.
In the thirteenth century, however, Albertus Magnus, who was equally active and influential in promoting natural knowledge and the study of the Aristotelian philosophy, possessed a hot-house in the convent of the Dominicans at Cologne.
This celebrated man, who had already fallen under the suspicion of sorcery on account of his speaking-machine, entertained the king of the Romans, Wilhelm of Holland, on the 6th of January, 1249, i
e surrounding the disk a, which in falling to its seat is prevented from coming immediately in contact with the metal, the water acting as a cushion.
The disk and seat therefore are not distorted by hammering, and the valve is almost noiseless in its action.
An instrument to indicate the time by the passage of water into or from a vessel.
A more modern form of water-clock was invented in the seventeenth century, probably by an Italian ecclesiastic at Bologna; or by a pewterer at Sens, in Burgundy.
It consists of a cylinder divided into several small cells, and suspended by a thread fixed to its axis, in a frame on which the hour distances, found by trial, are marked out. As the water flows from one cell into the other, it changes very slowly the center of gravity of the cylinder and puts it in motion, much like the quicksilver puppets invented by the Chinese.
Beckmann refers to an alarm-apparatus attached to one of these clocks which cons