GRE 
Gravity, in music, is the modification 
of any sound by which it becomes deep or 
low in respect of some other sound. The 
gravity of sounds depends on the thickness 
and distension of the chords, or the length 
and diameter of the pipes, and in general 
on the mass, extent, and tension of the so- 
norous bodies. The larger and more lax 
the bodies, the slower will be the vibrations 
and the graver the sounds. 
GREASE, See Farriery. 
GREAT circle sailing, the manner of 
conducting a ship in, or rather pretty near 
the arch of a great circle, that passes 
through the zenith of the two places, viz. 
from whence she'came, and to which she is 
bound. 
GREEK church. In the eighth century 
there arose a difference between the eastern 
and western churches, which, in the course 
of about two centuries and a half ended in 
a total separation. The Greek, or Eastern, 
or as it is sometimes called the Russian 
church, spread itself over the eastern parts 
of Europe. It bears a considerable resem- 
blance to the church of Rome, but denies 
the infallibility and supremacy of the Pope : 
it rejects also the worship of images, and 
the doctrine of consubstantiation, or the 
union of the body of Christ with the sacra- 
mental elements. The administration of 
baptism is performed by immersing the 
whole body. The Greek church has the 
game division of clergy, and the same dis- 
tinction ranks and offices with the church 
of Rome. 
GREEN, one of the original colours ex- 
cited by the rays of light. See Chroma- 
tics, Colours, and Optics. The green 
colour of plants has been shown, by the 
French chemists, to depend upon the ab- 
sorption of carbonic acid, and it is supposed 
that the leaves of plants have the power of 
decomposing the carbonic acid and water 
also ; the oxygen they emit, while the car- 
bon and hydrogen enter into the compo- 
sition of the inflammable parts of the plant. 
Green, Brunswick, a pigment used by 
German artists, and known in our shops un- 
der that name. It is made by saturating 
cold water with muriated ammonia, and 
adding three times as much copper clipping 
as ammonia. The moisture is to be evapo- 
rated, taking care that no dust be allowed 
to get to. it. The muriate of ammonia is 
decomposed by the copper, which is itself 
corroded and converted into a green oxide. 
It is then to be digested in successive por- 
tions of alcohol, as long as any green oxide 
GRE 
is taken up ; the solutions are now to be 
added together, and the liquor to be driven 
off by a moderate heat ; the residue is the 
pigment required. 
Green cloth, a board or court of justice, 
held in the counting-house of the king’s 
household, composed of the lord-steward, 
and officers under him, w'ho sit daily. To 
this count is committed the charge and over- 
sight of the king’s household in matters of 
justice and government, with a power to 
correct all offenders, and to maintain the 
peace of the verge, or jurisdiction of the 
court-royal; which is every way about two 
hundred yards from the last gate of the pa- 
lace where his Majesty resides. It takes its 
name, board of green-cloth, from a green 
cloth spread over the board where they sit. 
Without a warrant first obtained from this 
court, none of the king’s servants can be 
arrested for debt. 
Green finch. See Fringilla. 
GREENHOUSE, or conservatory, a 
house in a garden contrived for sheltering 
and preserving the most tender and curious 
exotic plants, which, in our climate, will 
not bear to be exposed to the open air 
during the winter season. These are gene- 
rally large and beautiful structures, equally 
ornamental and useful, 
GREGORIAN calendar, that which 
shows the new and full moon, with the time 
of Easter, and the moveable feasts depend, 
ing thereon, by means of epacts, disposed 
through the several mopths of the Gregorian 
year, 
Gregorian epoch, the epocha, or time 
whence the Gregorian calendar or computa- 
tion took place. The year 1808 is the 
226th year of that epocha. 
Gregorian year, the Julian year cor- 
rected, or modelled, in such a manner as 
that three secular years, which in the Julian 
account are bissextile, are here common 
years, and only every fourth secular year is 
made a bissextile year. 
The Julian computation is more than 
the solar year by eleven minutes, which 
in one hundred and thirty-one years amounts 
to a whole day. By this calculation, the 
vernal equinox was anticipated ten days 
from the time of the general council of 
Nice, held in the year 325 of the Christian 
asra, to the time of Pope Gregory XIII, 
who therefore caused ten days to be taken 
out of the month of October, in 1582, to 
make the equinox fall on the twenty -first 
of March, as it did at the time of that coun- 
cil, and to prevent the like variation for the 
