asilj 
but it would prevent misconception, and 
obviate cavil upon this head, if the ex- 
pression inferior seamen were substituted 
for ordinary seamen, wherever it occurs 
in my statement. 
Rosert Parron. 
Hampshire, February 2, 1811. 
To the Editor of the Monthly Magazine. 
SIR, 
AVING paid some attention to the 
H astronomical quere in your last, I 
venture to submit the following ideas on 
the subject, by way gf an attempt at a 
solution. 
Although the moon contains only a 
fortieth part of the quantity of matter 
that the earth does, she is said to be the 
largest secondary planet in the system, 
in proportion to its primary. The argu- 
ment may therefore be most fairly stated 
as between these two, since it would 
apply yet more strongly to the others. 
The attraction of the moon upon the 
waters of the earth is just sufficient to 
raise a moderate and beneficial tide, 
which is met by the several places of the 
earth twice in each diurnal revolution: 
whereas if we were its secondary planet, 
and the primary one forty times our bulk, 
it would attract the waters with forty 
times the furce that they are now subject 
to; and consequently vast regions of the 
earth would twice in every day be inun- 
dated ; and a great additional inconve- 
nience would certainly result from the 
increased rapidity in the ebbing and 
flowing of the waters. It may indeed 
be doubted whether they would be at all 
navizable. But supposing that we (like 
the moon) always turned the same face 
towards our primary, then, although the 
waters which were under and opposite 
to it would be greatly raised by its at- 
traction ; yet as they would remain con- 
stautly in the same state, (except such 
gentle variations as might restilt from 
eauses hereafter to be noticed) the effect 
arising from the diiference of bulk would 
be the same as if there were no tide at 
all; so that none of the above inconve- 
niences would be perceived. 
it is evident therefore that the moon 
can have no sensible tides resulting from 
the eartl’s attraction, except what arise 
from the. variation in the degree of that 
attraction, in consequence of the changes 
of distance; and as her eccentricity 3s 
‘considerable, and the earth so large a 
body, itis probable that this change of 
distance may have the effect of produc- 
dug a gentle tide, whereby the waters 
f- 4 
Phenomena of the Boon. 
$18 
‘under and oppusite to the earth will be 
highest-in the périgeon and lowest in the 
apogeon. There will consequently be 
high water and. low water once in about 
twenty-eight of our days, or a periodical 
month, which is not quite equal to a day 
and night in the moon, Besides this, 
the attraction of the sun will also pro» 
duce another tide, (as it does with us), 
returning to all parts of the moon twice 
in a Junation or synodical month, which 
is the lunar day and night. 
TYhe varying positions of the sun and 
moon will produce either spring or neap 
tides, according as their actions concur 
with, or counteract, each other, and the 
greatest spring tides in the parts directly 
under, and opposite to, the earth, being 
when the sun is in the moon’s perigeon 
at the conjunction, orin her apogeon at 
the opposition; and the lowest neap 
tides when the moon is in her apogeon 
ata quadrature. In the circle, ninety 
degrees from those points, or what we 
call the moon’s limb, the contrary will 
take place. The fluctuations of the lu- 
nar waters, arising from these causes, are 
probably sufficient to preserve their sweet- 
hess, and to answer other purposes of 
convenience, as the tides do with us. 
In the above theory it is taken for 
granted that lunar seas exist, which L 
find is denied by some philosophers, and 
I observe that the one, who is possessed 
of the most powerful apparatus for ob= 
servation, speaks of the moon as if it 
were decidedly not a terraqueous globe. 
Others however are of a different way of 
thinking, and there seem to be good ar- 
guments for their opinions : but which- 
ever way that question be decided, J ap- 
prehend it is agreed on all hands that 
the moon is furnished with an atmo- 
sphere, and the reasoning above may be 
applied to that, although there should be 
no seas. For I presume it to be indis- 
putable that the earth and mocn,: by 
their attraction, raise tides in each other's 
atmosphere, and that the air m the pro- 
tuberant parts must be thereby consi= 
derably rarified, and in those remote 
from them, as much condensed; both 
which effects must be abundantly greater 
in the moon than on theearth. It might 
therefore be a serious inconvenience to 
the former if so considerable an alter- 
ation in the state of the air were to re- 
eur at all places successively at short 
jatervals of time, as the Udes,of the same 
nature do with us; for besides their ef. 
fect (or influence as it is called) on the 
minds and bodies of 4a unfortunate de- 
acriplion 
