Gill 



OLA 



GIMBLETING, a term applied to the 

 anchor, to denote the action of turning it 

 round by the stock, so that the motion of 

 the stock appears similar to that of the 

 handle of a gimblet when it is employed. 



GIN. See GENEVA. 



Gix, in mechanics, a machine for driv- 

 ing piles, fitted with a windlass and 

 winches at each end, where eight or nine 

 men heuve, and round which a rope is 

 reeved that goes over the wheel at the 

 top. 



G1NANNIA, in botany, a genus of the 

 Enneandria Monogynia class and order. 

 Natural order of Lomentacex. Legumi- 

 nos<e, Jussieu. Essential character : calyx 

 double, both one-leafed; petals three, 

 fringed, spreading; germ pedicelled, 

 with a membranaceous wing at top ; le- 

 gume. There is but one species, viz. G. 

 guianensis, a shrub about fifteen feet high; 

 a native of the forests of Guiana. 



GINGER, in botany. See ZINZIBEB. 



GINORA, in botany, so called in ho- 

 nour of the Marquis Carlo Ginori, a ge- 

 IHIS of the Dodecandria Monogynia class 

 and order. Natural order of Salicarise, 

 Jussieu. Essential character : calyx six- 

 cleft; petals six; capsule one-celled, four- 

 valved, coloured, containing many seeds. 

 There is but one species, viz. G. Ameri- 

 cana, an elegant little shrub about four 

 feet high ; it is a native of Cuba, grows by 

 river sides, and called there rosa del rio, 

 or river rose. 



GINSENG, in botany. See PAKAX. 



GIRDERS, in architecture, some of the 

 largest pieces of timber in a floor. Their 

 ends are usually fastened into summers 

 and breast-summers, and joists are framed 

 in at one end to the girders. The size of 

 girders and summers, upon the rebuild- 

 ing of London, were fixed, by act of Par- 

 liament, to be in length from ten to twen- 

 ty-six feet, in breadth from eleven to se- 

 venteen inches, and in depth from eight 

 to fourteen inches. It was also fixed by 

 the same statute, that no girder or sum- 

 mer should be less than ten inches in the 

 wall, and that their ends should be laid in 

 loam ; as also that they be of good oak, 

 as free from knots as may be, because the 

 least subject to breaking, and may with 

 more safety be relied on in cross and 

 transverse work. 



GIRT, in the measuring of timber, is 

 the circumference of a tree, though some 

 use this word for the fourth part of the 

 circumference only, on account of the 

 use made of it. The square of the fourth 

 part is considered as equal to the area of 

 the section of the tree, which square 

 therefore, multiplied by the length of the 



tree, is accounted the solid content. This 

 content is about one fourth less than the 

 true quantity, being nearly equal to what 

 it will be after the tree is hewn square, 

 and is probably intended to make an al- 

 lowance for the squaring the tree. 



GIRT, in naval affairs, the situation of a 

 ship which is moored so tight by her ca- 

 bles as to be prevented turning to any 

 change of the wind or tide, to the current 

 of which her head would otherwise be di- 

 rected. The cables, to produce this, are 

 extended by a strong application of me- 

 chanical powers within the ship, so that 

 as she veers, or endeavours to swing 

 about, her side bears upon one of the ca- 

 bles, which interrupts her in, the act of 

 traversing. 



GIRTH line, a rope passing through a 

 single block on the head of the lower 

 masts, to hoist up the rigging, and the 

 persons employed to place the rigging 

 and cross-trees on the mast heads. The 

 girth-line is the first rope employed to rig 

 a ship, after which it is removed till the 

 ship \s to be unrigged. 



GISEKIA, in botany, so named in no- 

 nour ot Paulus Dietericus Giseke, a genus 

 of the Pentandria Pentagynia class and 

 order. Natural order of Succulents. Por- 

 tulacex, Jussieu. Essential character: ca- 

 lyx five-leaved ; corolla none ; capsule 

 five, approximating, roundish, one-seed- 

 ed. There is but one species, viz.. G. 

 pharnacioides, trailing Gisekia, an annual 

 plant, and a native of the East Indies. 



GIVEN, among mathematicians and 

 philosophers, the same with data. If a 

 magnitude be known, or we can find an- 

 other equal to it, it is said to be given in 

 magnitude. Or when the position of any 

 thing is known, it is said to be given in 

 position : when the diameter or radius of 

 a circle is known, the circle is given in 

 magnitude. The circle is given in posi- 

 tion, when the position of the centre is 

 given. See DATA. 



GLABRARIA, in botany, a genus of the 

 Polyadelphia Polyandria class and order. 

 Essential character: calyx five-cleft; pe- 

 tals five; nectary composed of bristles the 

 length of the calyx; stamens thirty, al- 

 ways in sixes ; pericarpium a drupe. 

 There is but one species, viz, G. tersa, u 

 large tree resembling the champhor tree, 

 the wood of which is very light and pale 

 coloured, and not being liable to rot or to 

 be injured by insects, it is much used for 

 building both houses and ships. It is a 

 native of the East Indies. 



GLACIERS. Those vast piles of eter- 

 nal ice, with which it has pleased the au- 

 thor of nature to crown the immense 



