GAH 



&AL 



Yttria 35. 



Silica ..... 25.5 



Iron 25.0 



Oxide of manganese 2.0 



Lime 2.0 



"Water and carbon . 10.5 



100.0 



It has been found no where but at Yt- 

 'terby, in Sweden. 



GJERTNERA, in botany, in memory 

 of Joseph Gartner, M. D. F. R. S. a ge- 

 nus of the Decandria Monogynia class 

 and order. Essential character : calyx 

 five-parted, the leaflets having on the out- 

 side a single marginal gland ; corolla five- 

 ipetalled, somewhat unequal, tooth-letted, 

 furnished with very short claws; seed 

 vessel nearly globose, with four wings. 

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

 mosa, a native of the East Indies, in the 

 Circar mountains. 



GAFF, in naval affairs, a sort of boom 

 used in small ships, to extend the upper 

 edge of the mizen, and employed for the 

 same purpose on those sails, whose fore- 

 most edges are joined to the masts by 

 Loops or lacings, and which are usually 

 extended by a boom below ; such are the 

 mainsails of sloops, brigs, and schooners. 

 Gatf top -sail, is a light quadrilateral sail, 

 the head being extended on a small gaff, 

 which hoists on the top-mast, and the 

 foot spreading from the throat to the ex- 

 tent of the lower gaff. 



GAGE, in the sea language. When 

 one ship is to windward of another, she 

 is said to have the weather-gage of her. 

 They likewise call the number of feet 

 that a vessel sinks in the water, the ship's 

 gage : this they find by driving a nail 

 into a pike near the end, and putting it 

 down beside the rudder till the nail 

 catch hold under it ; then as many feet 

 as the pike is under water is the ship's 

 gage. 



GAGE, among letter-founders, a piece of 

 box or other hard wood, variously notch- 

 ed; the use of which is to adjust the 

 dimensions, slopes, &c. of the different 

 Sorts of letters. 



GA.GE, sliding, a tool used by mathemati- 

 cal instrument makers, for measuring and 

 setting off distances. It is also of 

 use in letter-cutting, and making of 

 moulds; 



GAHNIA, in botany, so named in ho- 

 nour of Henry Gahn, a genns of the Hex- 

 andria Monogynia class and order. Essen- 

 tial character : glume two vajved, irregu- 



lar; wectary two-valved, involving the fi- 

 laments ; stigma dichotomous. There are 

 two species. 



GAINAGE, in old law books, properly 

 signifies the plough-tackle, or implements 

 of husbandry ; but is also used for the 

 grain or crop of ploughed lands. 



GALANTHUS, in botany, snow-drop, a 

 genus of the Hexandria Monogynia class 

 and order. Natural order of Spathaceae, 

 Narcissi, Jussieu. Essential character: 

 petals three, concave ; nectary of three 

 small emarginate petals ; stigma simple. 

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

 snow- drop. 



GALARDIA, in botany, a genus of the 

 Syngenesia Polygamia Frustranea class 

 and order. Natural order of Corymbiferae- 

 Essential character : receptacle chaffy ; 

 seed crowned with the five-leaved caly- 

 cle ; calyx of two rows of scales almost 

 equal. There is only one species, viz. G, 

 alterni-folia. 



GAL AX, in botany, a genus of the Pen- 

 tandria Monogynia class and order. Es- 

 sential character : calyx ten-leaved ; co- 

 rolla salver-shaped ; capsule one-celled, 

 two-valved, elastic. There is but one 

 species, viz. G. aphylla. 



GALAXIA, in botany, a genus of the 

 Monadelphia Triandria class and order. 

 Natural order of Ensatae. Irides, Jussieu. 

 Essential character : spathe one-valved ; 

 corolla one-petalled, six-cleft ; tube capil- 

 lary ; stigma many-parted. There are 

 two species, both natives of the Cape of 

 Good Hope. 



GALAXY, in astronomy. A very re- 

 malkable appearance in the heavens is 

 that called the galaxy, or the milky-way. 

 This is a broad circle, sometimes dou- 

 ble, but for the most part single, sur- 

 rounding the whole celestial concave. 

 We perceive also in different parts of 

 the heavens small white spots, which ap- 

 pear to be of the same nature with the 

 milky-way. These spots are called ne- 

 bula. 



With a powerful telescope, Dr. Her- 

 schel first began to survey the via lactea* 

 and found that it completely resolved the 

 whitish appearance into stars, which the 

 telescope he formerly used had not power 

 enough to do. The portion he first ob- 

 served was that about the hand and club 

 of Orion ; and found therein an astonish- 

 ing multitude of stars, whose number he 

 endeavoured to estimate, by counting 

 many fields, and computing from a mean 

 of these how many might be contained 

 in a given portion of the milky-way. In 

 the most vaeant place to be met with in 



