Guelfs, a celebrated faction in Italy, antagonists of the Gibelins. See Gibelins.
The Guelphs and Gibelins filled Italy with blood and carnage for many years. The Guelphs stood for the Pope, against the emperor. Their rise is referred by some to the time of Conrad III. in the twelfth century; by others to that of Frederick I.; and by others to that of his successor Frederick II. in the thirteenth century.
The name of Guelph is commonly said to have been formed from Welf, or Welfo, on the following occasion: the emperor Conrad III., having taken the duchy of Bavaria from Welf VI., brother of Henry duke of Bavaria, Welfe, assisted by the forces of Roger king of Sicily, made war on Conrad, and thus gave birth to the faction of the Guelphs.
Others derive the name Guelfs from the German Wolff, on account of the grievous evils committed by that cruel faction: others deduce the denomination from that of a German called Guelle, who lived at Pi-floey; adding, that his brother, named Gibel, gave his name to the Gibelins. See the article Gibelins.
Gelderland, one of the united provinces, bounded on the west by Utrecht and Holland, on the east by the bishopric of Munster and the duchy of Cleves, on the north by the Zuider Sea and Overijssel, and on the south it is separated from Brabant by the Maes. Its greatest extent from north to south is about 47 miles, and from west to east near as much; but its figure is very irregular. The air here is much healthier and clearer than in the maritime provinces, the land lying higher. Excepting some part of what is called the Veluwe, the soil is fruitful. It is watered by the Rhine, and its three branches, the Wahal, the Yssel, and the Leek, besides lesser streams. In 1079, it was raised to a county by the emperor Henry IV. and in 1339 to a duchy by the emperor Louis of Bavaria. It had dukes of its own till 1528, when it was yielded up to the emperor Charles V. In 1576, it acceded to the union of Utrecht. It is divided into three districts, each of which has its states and diets. Those for the whole province are held twice a-year at the capital towns. The province sends 19 deputies to the states-general. Here are computed 285 Calvinist ministers, 14 Roman Catholic congregations, 4 of the Lutheran persuasion, besides 3 others of Remonstrants and Anabaptists. The places of most note are Nimuegen, Zutphen, Arnhem, Harderwyk, Loo, &c.
Geldres, a strong town of the Netherlands, in the duchy of the same name. It was ceded to the king of Prussia, by the peace of Utrecht, and is seated among marshes. E. Long. 6°. N. Lat. 51° 30'. It surrendered to the French in 1794.
Guercino. See Barberi.
Guericke, Otto or Ortho, a German philosopher of considerable eminence, was born in 1602, and died at Hamburg in 1686. In conjunction with Torricelli, Pafchel, and Boyle, he contributed much to the farther explanation of the properties of air. He was counsellor to the elector of Brandenburg, and burgomaster. Guericke, gomaller of Magdeburg, but his greatest celebrity was derived from his philosophical discoveries, in a particular manner the invention of the air-pump. Mr Boyle indeed made approaches towards the discovery of it much about the same time, but with that candour which is ever the characteristic of great and enlightened minds, he confessed that the merit of it belonged exclusively to Guericke, the account of whose experiments first enabled him to bring his design to anything like maturity. Our author has also the merit of inventing the two brass hemispheres, by which the pressure of the air is illustrated, and an instrument for determining the changes in the state of the atmosphere, which fell into disuse on the invention of the barometer. By consulting his tube he predicted approaching storms, on which account he was deemed a sorcerer by the ignorant multitude. It is worthy of observation, that when his brass hemispheres were applied to each other, and the air exhausted, it resisted the efforts of fifteen horses to draw them asunder. He composed several treatises in natural philosophy, the principal of which is entitled *Experimenta Magdeburgica,* 1672, folio, which contains his experiments on a vacuum.
GUERNSEY, an island in the English channel, on the coast of Normandy, subject to Britain; but (as well as the adjacent islands) governed by its own laws. See JERSEY. It extends from east to west in the form of a harp, and is thirteen miles and a half from the south-west to north-east, and twelve and a half, where broadest, from east to west. The air is very healthy, and the soil naturally more rich and fertile than that of Jersey; but the inhabitants neglect the cultivation of the land for the sake of commerce: they are, however, sufficiently supplied with corn and cattle, both for their own use and that of their ships. The island is well fortified by nature with a ridge of rocks, one of which abounds with emery, used by lapidaries in the polishing of stones, and by various other artificers.—Here is a better harbour than any in Jersey, which occasions its being more resorted to by merchants; and on the south side the shore bends in the form of a crescent, enclosing a bay capable of receiving very large ships. The island is full of gardens and orchards; whence cider is so plentiful, that the common people use it instead of small beer, but the more wealthy drink French wine.