GER 



GES 



and equal to EC ; draw FC : the parallel- 

 ogram contained under ECDF will equal 

 the area of the pentagon. Or the penta- 

 gon may be changed to a triangle by add- 

 ing 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 semi- 

 circle DE, and then shift to D for a cen- 

 tre, and make the semicircle AE in the 

 opposite side of the line : shift again from 

 D to C for a centre, and draw the semi- 

 circle 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 geo- 

 metry to its pristine intent, namely, the 

 measurement of land, we must refer our 

 readers to SUHTEYING; under which head 

 it will be found practically exemplified. 

 We trust sufficient has been here said to 

 show the utility and purposes of this im- 

 portant science, and to prove serviceable 

 to such persons as may not have occasion 

 for deep research, or for extensive detail. 



GEORGIC, a poetical composition up- 

 on the subject of husbandry, containing 

 rules therein, put into a pleasing dress, 

 and set off with all the beauties and em- 

 bellishments of poetry. 



GEORGINA, in botany, a genus of 

 the Syngenesia Superflua class and order. 

 Receptacle chaffy ; no down ; calyx dou- 

 ble ; the outer many -leaved ; inner one- 

 leaved, 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, fas- 

 tened 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 Angi- 

 ospermia class and order. Natural order 



of Personatx. Scrophulariae, 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. 



GERMINATION. When a seed is 

 placed in a situation favourable to vege- 

 tation, 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 heat 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, whick 

 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 1 to the knowledge 

 of botanists, might hence appear the re- 

 sult 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 malt- 

 ing in darkened apartments, malting be- 

 ing nothing more than germination, 

 conducted with a particular view. 



GEROPOGON, in botany, a genus of 

 the Syngenesia Polygamut JEqualis class 

 and order. Natural order of Composite 

 Semiflosculosae, or compound flowers, 

 with semi-florets or ligulate florets only. 

 Cichoraceae, Jussieu. Essential charac- 

 ter: calyx simple; receptacle with bris- 

 tle-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, 



