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moo
( 80 )
MOO
iLear the Moon's Body; and rarer above, Now as the Air be
which incompaffes our Earth is fuch a Fluid, it is manifeft it
there is Air about the Moon; and fince the different Denfity fun
of the Air depends on its different Gravity and Elaflicity, mi
no doubt the different Denfity of the Lunar Air has the M
fame Caufes. Again, we have obferv'd the Lunar Air is R,
not always equally clear and tranfparent: fometimes it
changes the fphericaI Figures of the Stars into Ovals; and na
in the feveral total Eclipfes ju{l mentioned, there was gr
obfcrved a trembling in the Moon's Limb, immediately Ih
before immerfion, with an Appearance of thin, light
Smoak flying over it during immerfion, very apparent in is
England. And hence, as thefe fame Phenomena are ob- fo
ferved in our Air when full of Vapours, it is pretty plain, re
at the time when thefe Phenomena are obferved in that of fic
the Mloon, it is full of Papours and Exhalations. And, St
llfly, fince at other times the Lunar Air is clear and tranf- er
parent, producing none of thefe Phxnomena, the Va- tb
pours mud have been precipitated on the Moon ; and there-
fore either Dew, or Rain, or Snow have fallen.      dt
7. The Moon is a lody in all refpegls like our Earth, and if
fittedfor tbefame purpofJs. For we have fhewn that it is P.
Denfe-Opake-has Mountains and Valleys-Seas, with
IJlands, Penmnfulhe, Rocks, and Promonrories- a changeable ti
Amtnojbere, wherein 1"apours and Exhalations rife and fall 1
-Day and Night; a Sun to illumine the one, and a Moon  V
the other,- Slimmer and Winter, &c.                 tl
From thefe, by Analogy, may infinite other Properties st
and Appendages of the Moon be deduced: From the C
Changes in the Atmofphere will follow Winds, and other oi
Meteors; and according to the different Seafons of the t]
Year, Rain, is, Froft, Snow, E&c. From  the Inequali- v
ties upon the Moon's Surface will arife Lakes, Rivers, C
Springs, E$'c. it
Now Nature, we know, produces nothing in vain: Rains 1:
and Dews fall on our Earth to make Plants vegerate ; and C
Plants take Root, grow, produce Seeds and Fruits for Ani- r,
mals to feed on. But Nature is flill uniform and confident f
with herfclf, and like things ferve for like Ends : Why  1
then may not there be Plants and Animals in the Moon ? t'
To what other purpofe fo nice a Provifion for them ?  t
Thefe Arguments * ill receive new force when we come t
to fhew that our Earth itfelf is a Planet; and that when
viewed from the other Planets, it appears, in fome, like the
Noon in others, like Venus ; in others, Jupiter, &c. A Simi-
litude between the Planets, both Optical and Phyfical, be-t
ing a ffrong Prefumption their Furniture is alike. SeeI
EARTHand PLANET.                                     I
To meafure the Height of the Mountains of the MOON.
Suppofe E D  (Fig. 19.) the Moon's Diameter, E CD  -
the Boundary of Light and Darknefs; and A the Top of
the Hill in the dark part beginning to be illumined
With a Telefcope obferve the Proportion (of A E, or the
diflance of A from the Line where the Light commences,
to the Diameter of E D : Here we have two fides of a
reaangled Triangle A E, C A; the Squares of which    i
added together give the Square of the third; whence the
Semi-diameter C D being fubfilracded, leaves A B, the
Height of the Mountain.
Ricciolus, v. g. found the Top of the Hill St. Catherine
illumined at the diflance of  of the Moon's Diameter from
the Confines of Light. Suppofing, therefore, C E, 8 5
and A E, I ; the Squares of the two will be 65, whofe
Root is 8.c6z the length of A C ; fubilraaing therefore
B C = 8, the Remainder is AB= o6z. The Moen's
Semi-diameter, therefore, is to the Mountain's height as
8 is to o.6z ; i.e. as 8o0 to 6z. Suppofing, therefore, the
Diameter of the Moon i :82 Eszglifi Miles, by the Rule of
Three we find the height of the Mountain 9 Miles.
The Heights, Oc. of the Lunar Mountains being mea.
furable, Afironomers have taken occafion to give each its
Name. Ricciolus, whom mof others now follow, diflin-
guilhed them by the Names of the Celebrated Aflronomers;
and by thefe Names they are fdill expreffed in Obfervations
of the Lunar Eclipfe, tec. See the Figure, (Tab. ASTRO-
NOMY, Fig. g0.)
The apparent Magnitude of the MooN.
The Magnitude of the Moon, at rifing and fetting, is a
Phaenomenon that has extremely embarraffed the modern
rhilofophers. According to the ordinary Laws of Vifion, it
Should appear the lead when neared the Horizon, as being
then neared to the Eye ; and yet we find the contrary true
in faa. Des Cartes, and from  him  Dr. Wallis, and mod
other Authors, account for this from the long Series of Ob-
jeals interposed between the Eye and the Extremity of the
fenfible fHorizon, which make us imagine it more remote
than when in the Meridian, where the Eye fees nothing in
the way between the Objea  and itfelf  This Idea of a
great diflance, makes us imagine the Moon the bigger:
For any Objedt being feen under any certain Angle, and
lieved, at the fame time, very remote,we naturally judge
mu*t be very large, to appear under fuch an Angle at
:h a diflance. And thus a pure Judgment of the Soul
lkes us fee the Moon bigger in the Horizon, than in the
eridian ; norwithilanding its Image painted on the
etina is lefs in the former Situation than the latter.
This Hypothefis, F. Guuye deftroys, by obferving that the
rrower and more confined the fenfible Horizon is, the
eater does the Moon appear; the contrary of which
ould happen on the Principle laid down.
Gaffenkdi is of opinion, that the Pupil of the Eye, which
always more open as the Place is more dark; being more
in the Morning and Evening than at other times, by
afon the Earth is covered with grofs Vapours ; and be-
ies, being obliged to pafs through a longer Column or
eries of'em, to reach the Horizon, the Image of the Moon
iters the Eye at a greater Angle, and is really painted
ere greater.
In anfwer to which, it mufd be faid, that notwithilanding
his dilatation of the Pupil, occafion'd by the Obfcurity j
the Moon be viewed through a little pin-hole made in a
saper, {he appears lefs when in the Horizon.
F. Gouye finding both the Conjeaures falfe, advances a
lird : He is of opinion then, when the Moon is in the
Horizon; the neighbourhood of the Earth, and the grofs
Tapours wherewith the Moon then appears inveloped, have
ie fame Effe~l, with regard to us, as a Wall, .or o-
ier denfe Body placed behind a Column; which in that
afe appears bigger than when infulate, and incompalfed
a all fides with an illumined Air. Further, it is obterved
hat a Column when fluted, 'appears bigger than before,
when it was plain; the Flutes being fo many particular
)bjects, which by their Multitude occafion the Mind to
inagine the whole Objed whereof they are compofedof a
irger extent. The fame thing may be faid of the feveral
)bjecs feen towards the Horizon, to which the Moon cor-
efponds at her Riuing and Setting. And hence it is that
he appears greater Rill, when fhe rifts or fets between
[rees; the narrow, yet diflind Intervals whereof have
he fame Effed with regard to the apparent Diameter of
he Moon, as a greater number of Flutes with regard to
he Shaft of a Column.
For the Eclqpfes of the MOON, fee ECLIPSES.
For the MOON'S Parallax, fee PARALLAX.
Tofindthe MOON'S Age. To the Day of the Month add
the Bpac1 of the Year, and the Months from March inclu-
five. The Sum, if under 30; if over, the Excefs is the
Moon's Age. If the Month have but 3o Days, the Excefs
ibove 29 is the Moon's Age.
To find the Time of the MooiN's being in the Meridian,
Dr Southing: Multiply her Age, if under I Days, by 4
and divide the Produa by 5; the Quotient gives the Hour,
and the Remainder multiplied by 12, the Minute. If her
Age exceed 15, fubifraln I5, and proceed with the Re-
mainder as before.
To find the Time of the MOON'S beginning tofLine. Mul-
tiply her Age, if under i5, by 48 t and divide the Produ&t
by 60: the Quotient gives the Hours ; and the Remainder
the Minutes. If her Age be above i5 Days, fubfira&
the time thus found, from 143 the Remainder gives the time
of lhining in the Morning.
MOOR, MORA, a Heath, or barren Tracl of Ground.
See HEATH.
It is fometimes alfo ufed for a Morafi, Mofs, or Fen. See
MOR ASS.
Mlora Misa, in antient Writings, particularly denotes a
Mofs, or Peat-Mofs.
MOORING, at Sea, is the laying out of Anchors, in a
proper place, for the fecure Riding of a Ship.  See
ANCIIOR.
To Moor a-crofs, is to lay out one of the Anchors on one
fide, or a-thwart a River, and the other right againft it.
To Moor along/, is to have an Anchor in a River, and a
Hawfer on Shore.
To Moor QLuarter-.fot, is to moor Quartering, between
the two firnl ways.
MOORING for Eaft, Weft, &c. is when they obferve
which way, and on what Point of the Compafs the Wind
or Sea is mod likely to endanger the Ship, and there lay
out an Anchor.
MOORS-HEAD, in Chymidry, a Copper-Cap made
in form of a Head, to be fet over the Chimney of a Re-
verberating Furnace. See REVERBERATORT.
MOORS-HEAD is alfo the Head of a Copper or Glafs-
Still or Alembic, which is luted on to the Body or Cucur-
bit, and hath a Beak or Pipe to let the Spirit run down into
the Receiver.
MOOT, a difficult Cafe, or Queflion argued by the
Students of Inns of Court, by way of Exercife. Sea
MOOTING.
The Word is formed either from the Saxon, Ahoting,
A~embly; or the French, Mot, Word,
MOOTING,