and equal to EC; draw FC: the parallelogram contained under ECDF will equal the area of the pentagon. Or the pentagon may be changed to a triangle by adding to AB four times its own length, and drawing a line from the centre, to the produced termination of AB; the angle at the centre would then be obtuse.

PROBLEM XXXIX.

To draw a spiral line from a given point. Fig. 37. Draw the line AB through the given point C, and from C draw the semicircle DE, and then shift to D for a centre, and make the semicircle AE in the opposite side of the line : shift again from D to C for a centre, and draw the semicircle FG; and then continue to change the centres alternately, for any number of folds you may require; the centre C serving for all above, the centre D for all below, the line AB.

With respect to the application of geometry to its pristine intent, namely, the measurement of land, we must refer our readers to SURVEYING; under which head it will be found practically exemplified. We trust sufficient has been here said to show the utility and purposes of this important science, and to prove serviceable to such persons as may not have occasion for deep research, or for extensive detail.

GEORGIC, a poetical composition upon the subject of husbandry, containing rules therein, put into a pleasing dress, and set off with all the beauties and embellishments of poetry.

GEORGINA, in botany, a genus of the Syngenesia Superflua class and order. Receptacle chaffy; no down; calyx double; the outer many-leaved; inner oneleaved, eight-parted. There are three species.

GERANIUM, in botany, crane's bill, a genus of the Monadelphia Decandria class and order. Natural order of Gruinales. Gerania, Jussieu. Essential character: calyx five-leaved; corolla five-petalled, regular; nectary five honied glands, fastened to the base of the longer filaments; fruit five-grained, beaked; beaks simple, naked, neither spiral nor bearded. There are thirty-two species. There are five species indigenous to the United States. The root of one of these, G. maculatum, or spotted crane's bill, is an astringent, and the decoction of it, made with milk, is useful in cholera infantum.

GERARDIA, in botany, so called in honour of John Gerarde, our old English botanist, a genus of the Didynamia Angiospermia class and order. Natural order

GERMINATION.

of Personatæ. Scrophulariz, Jussieu. Es sential character: calyx five-cleft; corolla two-lipped, lower lip three-parted, the lobes emarginate, the middle segments two-parted; capsule two-celled, gaping. There are ten species. When a seed is placed in a situation favourable to vegetation, it very soon changes its appear. ance; the radicle is converted into a root, and sinks into the earth; the plumula rises above the earth, and becomes the trunk or stem. When these changes take place, the seed is said to germinate; the process itself has been called germination, which does not depend upon the seed alone; something external must affect it. Seeds do not germinate equally and indifferently in all places and seasons; they require moisture and a certain degree of heat, and every species of plant seems to have a degree of beat peculiar to itself, at which its seeds begin to germinate; air also is necessary to the germination of seeds; it is for want of air, that seeds which are buried at a very great depth in the earth either thrive but indifferently, or do not rise at all. They frequently preserve, however, their germinating virtues for many years within the bowels of the earth; and it is not unusual, upon a piece of ground being newly dug to a considerable depth, to observe it soon after covered with several plants, which had not been seen there in the memory of man. Were this precaution frequently repeated, it would perhaps be the means of recovering certain species of plants which are regarded as lost; or which, perhaps, never coming to the knowledge of botanists, might hence appear the result of a new creation. Light is supposed to be injurious to the process, which af fords a reason for covering the seeds with the soil in which they are to grow, and for carrying on the business of malting in darkened apartments, malting be. ing nothing more than germination, conducted with a particular view.

GEROPOGON,' in botany, a genus of the Syngenesia Polygamia Equalis class and order. Natural order of Composite Semiflosculosa, or compound flowers, with semi-florets or ligulate florets only. Cichoraceæ, Jussieu. Essential character: calyx simple; receptacle with bristle-shaped chaffs; seeds of the disk with a feathered down of the ray, with five awns. There are three species.

GESNERIA, in botany, so named in honour of Conrad Gesner, of Zurich, the famous botanist and natural historian, a genus of the Didynamia Angiospermia,

class and order. Natural order of Personatæ. Campanulaceæ, Jussieu. Essential character: calyx five-cleft, sitting on the germ; corolla incurved and recurved; capsule, inferior, two-celled. There are twelve species.

GETHYLLIS, in botany, a genus of the Hexandria Monogynia class and order. Natural order of Spathacea. Narcissi, Jussieu. Essential character: calyx none; corolla six-parted; berry club-shaped; radicle, one-celled. There are four species.

GEUM, in botany, English avens, or herb bennet, a genus of the Icosandria Polygynia class and order. Natural order of Senticosa. Rosacea, Jussieu. Essential character: calyx ten-cleft; petals five; seeds with a kneed awn. There are nine species, natives of Europe and North America; seven belonging to North America.

GHINŢA, in botany, so named in me.

mory of Lucas Ghini, a famous physician and botanist of Bologna, a genus of the Diandria Monogynia class and order. Natural order of Personatæ. Vitices, Jussieu. Essential character: calyx fivetoothed, teeth acuminate; corolla twolipped; stamina four, with two barren anthers at the end of the shorter filaments; pericarpium a drupe containing four or five celled nuts, with a seed in each cell. There are two species.

GIANT's causeway, a vast collection of a black kind of marle, called basaltes, in the county of Antrim in Ireland. See BASALTES, and STAFFA.

GIBBOUS, in astronomy, a term used in reference to the enlightened parts of the moon, whilst she is moving from the first quarter to the full, and from the full to the last quarter: for all that time the dark part appears horned, or falcated; and the light one hunched out, convex or gibbous,