The Meta-Encyclopedia

Briefly noted: G (7)

Several of these 6 encyclopedias cover each subject below, but between them they say too little to fill a page of its own. They are gathered here so the accounts can sit side by side.

Gun

Aiton's Encyclopedia: a strong metal tube designed to direct the flight of a bullet or other projectile. The bullet is expelled forcibly by a gas due to the ignition of gunpowder or other explosive. In its original sense the term includes not only pistols, revolvers, shotguns, rifles, muskets, and firearms of every description, but the largest cannon as well. Guns, that is to say, small cannon, or firearms, were used in warfare for the first time at the battle of Crecy, 1346. See Firearms ; Cannon

Collier's New Encyclopedia: See AUTOMATIC GUN; FIREARMS; ORDNANCE; ARTILLERY; MACHINE GUN; EXPLOSIVES.

Covered by Aiton's Encyclopedia and Collier's New Encyclopedia

Gun Cotton

Collier's New Encyclopedia: pyroxylin. Trinitrocellulose, C&H (NO2) 30%, more probably a nitric ether of cellulose, C12H14 (ONO2) 604, as by the action of reducing agents as hydric potassium sulphide, KHS, and iron and acetic acid, it is converted into cellulose. Boiled with ferrous sulphate and concentrated hydrochloric acid, it gives off all its nitrogen as N2O2. Gun cotton was discovered by Schönbein in 1845. It is prepared by drying cottonwool at 100 and then leaving it for 24 hours in a mixture of one volume of nitric acid, specific gravity 1.5, and three volumes of sulphuric acid, specific gravity 1.85, the mixture being cooled to 10°. It is then washed with water, and, if required pure, again with a mixture of one part alcohol and three parts ether to remove the lower nitrates. Gun cotton finely divided explodes between 160°- 170°. It keeps best if it is washed with soda. Compressed gun cotton burns like tinder, but is exploded by mercuric-fulminate. See EXPLOSIVES.

Aiton's Encyclopedia: a violent explosive. It is prepared by soaking cotton waste in the same acids that form nitroglycerin. After washing and treatment too detailed for description, it may be used loose, or it may be compressed into small cakes like gun wads by a pressure of from four to six tons per square inch. It is almost smokeless, and is used as a substitute for gunpowder. It is the forerunner of dynamite by which it has been supplanted for purposes of blasting. See Dynamite

Covered by Collier's New Encyclopedia and Aiton's Encyclopedia

Gymnastics

Collier's New Encyclopedia: exercises of the body and limbs which tend to invigorate and develop their power. Gymnastic games are of very ancient origin. They are mentioned in the second book of the "Ili "Iliad," where playing at quoits and javelin hurling are mentioned. Later on games of this kind were dedicated to the gods, and the rewards being called "athla," gave origin to the name "athletes," applied to those who contend for them. Shortly before the time of Hippocrates, gymnastics were made a part of medicine, and gradually they were reduced into a complete system. Public buildings, called "gymnasia," were erected for the purpose, and officers for their superintendence were appointed by the state. Among the exercises practiced in these gymnasia were dancing, wrestling, boxing. ing, running, leaping, quoit-throwing, hurling, riding, driving, swimming, rowing, climbing ropes, swinging, mock fights of various kinds, etc. It is only since the commencement of the 19th century that gymnastic exercises have been revived as a science. GYNECOLOGY (jin-ē-kol'ō-ji or ginē-), that branch of medicine which treats of the diseases of women.

Aiton's Encyclopedia: . See Athletics

Covered by Collier's New Encyclopedia and Aiton's Encyclopedia