GAG 
assumes a reddish white colour, and remains 
unfused if the fragments are not very mi- 
nute ; with borax it is converted into a 
yellow-coloured glass. A new earth to 
Which the name of yttriahas been given, has 
been discovered in it : according to Vau- 
quelin it consists of 
Yttria 35. 
Silica.... 25.5 
Iron 25.0 
Oxide of manganese 2.0 
Lime 2.o 
Water and carbon 10 5 
100.0 
It has been found no where but at Ytter- 
by, in Sweden. 
G/ERTNERA, in botany, in memory 
of Joseph Ga-rtner, 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 outside a 
single marginal gland ; corolla five-petalled, 
somewhat unequal, tooth-letted, furnished 
with very short claws ; seed vessel nearly 
globose, with four wings. There is but one 
species, viz. G. racemosa, 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 foremost 
edges are joined to the masts by hoops or 
lacings, and which are usually extended by 
a boom below ; such are the main-sails of 
sloops, brigs, and schooners. Gaft' top sail, 
is a light quadrilateral sail, the head being 
extended on a small gaff, which hoists on 
the top mast, and the foot speading from 
the throat to the extent 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 cal! the number of feet that a ves- 
sel 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 w ood, variously notched ; 
the use of which is to adjust the dimen- 
sions, slopes, &c. of the different sorts of 
letters. 
Gage, sliding, a tool used by mathemati- 
cal instrument makers, for measuring and 
GAL 
setting off distances. It is also of nse in 
letter-cutting, and making of moulds. 
GAHNIA, in botany, so named in ho- 
nour of Henry Galin, a genus of tire Hexan- 
dria Monogynia class and order. Essential 
character : glume two valved, irregular ; 
nectary two-valved, involving the filaments ; 
stigma dichotomous. There are two spe- 
cies. 
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 : pe- 
tals three, concave ; nectary of three small 
emarginate petals; stigma simple. There 
is but one spdcies, viz. G. nivalis, snow- 
drop. 
GALARDIA, in botany, a genus of the 
Syngenesia Polygamia Frustranea class and 
order. Natural order of Corymbiferae. Es- 
sential character : receptacle chaffy ; seed 
crowned with the five-leaved calycle ; ca- 
lyx of two rows of scales, almost equal. 
There is only one species, viz. G. alterui- 
folia. 
GALAX, in botany, a genus of the Pen- 
tandria Monogynia class and order. Essen- 
tial character : calyx ten-leaved ; corolla 
salver-shaped; capsule one-eelled, 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- 
markable appearance in the heavens is that 
called the galaxy, or milky-way. This is a 
broad circle, sometimes double, but for the 
most part single, surrounding the whole ce- 
lestial concave. We perceive also in dif- 
ferent parts of the heavens small white 
spots, which appear to be of the same na- 
ture with the milky-way. These spots are 
called nebulae. 
With a powerful telescope, Dr. Herschel 
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 observed, was 
