DEC 
has thought proper, in perpeluum rei teflimonium, and for 
avoiding all dowbts and difficulties, to declare what the com- 
mon law is and ever hath been. Thus the ftatute of treafons, ~ 
25 Edw. IIT. c. 2. doth not make any new fpecies of trea- 
fon; but only, for the benefit of the fubjeét, declares and 
enumerates thofe feveral kinds of - Hae, which before 
were shige at the common law. 
DEC SION, in Grammar, the inflexion of a noun, 
ene 7 its divert cafes. See Case, Nominative, 
c. 
Mr. Harris obferves, that the aaa likened the 
noun in its primary and original for a perpendicular 
line ; and the ei Ae from the seein ae were Coaaaea 
as if that line fell from its perpendicular to an oblique pofi- 
tion: and hence the variations were called wlicus, ca/us, 
Grammarians were ia led to call the 
of enumerating the various cafes of a noun xAswis, 
“Zeclinatio, a declenfion ; hig it was a fort of progrefiive 
defcent from the noun’s upright form, through its various 
declining forms. Pieaies p. 277. 278. 
The declenfion of nouns is a different thing in the modern 
pee ie which ao not ie any ren from what it 
sin the ancient Greek and Latin, which hav 
Declenfion in languages, ae ein the nouns admit of 
changes, whether in the middle, peaings o or end. is pro- 
perly the expreffing or reciting a!l thofe changes in a certain 
order, and by certain degrees, called ca/e.. 
n languages wherein the nouns do not admit of changes 
in the fame number, declenfion is the expreffing of the differ- 
ent ftates or habitudes a noun is in, and the different relations 
it has: which difference of pip ide is marked by particles 
called articles ; as, a, the, of, to, from, &c. 
Decrension of adifeafe, is see it is paft its height, and 
the fymptoms abate. 
DECLINATION, of a celeftial objed, in a abides is 
its angular or perpendicular diftance from the equator, mea- 
ma meridian or great oe pafling eee ithe ob- 
jet and the poles of the heave 
A. great circle paffing in thie manner through the poles, 
(and sade perpendicular to the equator), is called a circle 
of declina 
Declina fies on the celeftial Jee Qy Rissa ete with lati- 
tude on the terreftrial. And in 
tio 
importance m practic nom — at the 
principal inftruments in nts cbferatorien a are coal nicied 
w to one or other of thefe operations. 
One of the moft dew: methods of amine the de- 
clination of a ftar is by means of its meridian altitude; for if 
this be given, and the latitude of the 
elination is eafily calculated by the tollowing rule: 
- the latitude of the place and zenith diftance of the 
re of different kinds, namely, one north, and the other 
feat ¢ their difference will be the dechmnation, ‘and it is of the 
fame kind as the latitude, when that is the greateft of the 
ollo modern aaa 
who clais the ftars according to their north polar 
The declinations of ‘all the ccledis bodies are coareeli 
Vou 
lace known, the de- . 
DEC 4 
arying. To obferve and explain the seni : thefe changes 
Meira belongs to the fcience of aft 
The change of ae a in the fan mre from his mo- 
tion in the ecliptic hen the obliquity of the ecliptic and 
the fun’s aoe te are oa the declination is eafily cal- 
culated by the folution of a right an gled d esidooe triangle ; 
or if the declination is obferved, the ae n’s | 
found by the fame method. ea yen n a 
equinoxes, the fun has no delice on a year, a 
the folftices, his Beas is the gteatett, bene she cal 
to the obliquity of the ecliptic 
The declination of the moon varies in a fimilar manner to 
ly, a 
m 
ferved to take place in ‘the declination of the fu 
courfe of a year, occur to the moon in the {pace of a month. 
Twice during this period the mogn croffes the equator, and 
therefore has no declination, and twice its declination is at 
amaximum. But the quantity of its greateft declination, 
n one revolution, a exceedingly variable, being fometimes 
oa to the fum of the obliquity of the ecliptic, and the 
inclination of the moon 
motio the moo 
which fucceffively change their A cieoua aout the cclintie 
in the {pace of about eighteen 
__ The greateft and leatt declnations, both north and fouth, 
appen n when oints. Thi s will 
. eafily nnderftood by confulting a ecletal globes or by refer- 
ring to PlateV. Afronomy, fig. 44, where op & op! reprefents 
the paises hen the alcending node isin YP, i moon’s 
orbit hes above or without the ecliptic a <n wy’ and its 
grete dectinton, m p, is equal to the obliquity of if fclip: 
lus t fo 
and p’n', orthe difference between the obliquity 
of the ane and the incliaation of the moon’s orbit. 
he declinations of the ae likewife vary from the 
intricate combinations of their refpeGtive motions with that 
of the tes ‘he de cece of the planets which are 
neareft ta us vary more rapidly, and with a greater apparent 
inegolaity on thofe more remote. 
e changes that take place in the declinations of the 
longitude of every ftar equally and uniformly, but the de- 
chnation of a ftar being its pofition relative to a different 
circle to that in which its motion in longitude is performed, 
the declination of fome ftars will be more affeted by this ree 
deere than that of others. When the motion in longie 
3 whic 
cenh 
wee this chance of declination common to all ftar: ars, 
This ig 
ound b 
proper motions d 
any certain rule cae on their pevation, yet Dr. Herf- 
thei thiuks many of them may be explained by a poo a 
Ce te 
