WEST LONGITUDE 90 deg. TO 60 deg.
KASTNER.--A large walled-plain at the S. end of the Mare Smythii, too
near the limb for satisfactory observation.
MACLAURIN.--The principal member of a group of irregular ring-plains on
the W. side of the Mare Foecunditatis, a little S. of the lunar equator.
Schmidt shows no details within it, except a small crater on the E. side
of the floor.
WEBB.--A ring-plain E. of Maclaurin, about 14 miles in diameter, with a
dusky floor, enclosed by a bright rim, on the N.E. side of which there is
a small crater. Schmidt seems to have overlooked the central hill.
LANGRENUS.--This noble circumvallation, the most northerly of the
meridional chain of immense walled-plains, extending for more than 600
miles from near the equator to S. lat. 40 deg., would, but for its
propinquity to the limb, rank with Copernicus (which in many respects it
resembles) among the most striking objects on the surface of the moon.
Its length is about 90 miles from N. to S., and its breadth fully as
much. In shape it approximates very closely to that of a foreshortened
regular hexagon. The walls, which at one point on the E. rise to an
altitude of nearly 10,000 feet, are continuous, except on this side,
where they are broken by the interference of an irregular depression, and
on the extreme S., where they are intersected by cross-valleys. Within,
the terraces are remarkably distinct, and the intervening valleys
strongly marked. The brilliant compound central mountain rises at its
loftiest peak to a height of more than 3000 feet. On the N. of it is an
obscure circular ring, which may possibly merely represent a fortuitous
combination of ridges, though it has all the appearance of a modified
ring-plain. On the Mare, some distance N.E. of the formation, is a group
of three ring-plains, with two small craters (associated with a ridge) on
the N. of them. Two of the more westerly of these objects have prominent
central mountains, and the third a very dark interior. At least three
bright streaks originate on the E. flank of Langrenus, which, diverging
widely, traverse the Mare Foecunditatis.
[FLATTENINGS ON THE MOON'S WESTERN LIMB.--About thirty years ago, the
Rev. Henry Cooper Key drew attention to certain flattenings which he had
noted on the W. limb, which are very apparent under favourable conditions
of libration. Their position cannot be closely defined, but the principal
deviation from circularity extends from about S. lat. 10 deg. to the
region on the limb opposite the S. border of the Mare Crisium.]
VENDELINUS.--The second great enclosure pertaining to the meridional
chain--a magnificent walled-plain of about the same dimensions as the
last. It is bounded by a very irregular rampart, which, under evening
illumination, is especially noteworthy, though nowhere approaching the
altitude of that of Langrenus. Its continuity on the W. is broken by the
great ring-plain Vendelinus C, about 50 miles in diameter, a formation
resembling Langrenus in miniature. This is hexagonal in shape, and has
many rings and depressions on its W. wall. South of Vendelinus C, the
wall of Vendelinus runs up in a bold curve to the fine terraced ring-
plain Vendelinus B, and is surmounted by a bright serpentine crest, and
traversed by several valleys running down the slope to the floor. B has a
small crater on its N. wall, and another in the interior. There is a wide
gap in the S. border of Vendelinus, which is partially occupied by
another somewhat smaller ring-plain, bounded by a southerly extension of
the E. wall, which includes on its outer slope many craters and other
depressions, and abuts near its N. end on the large ring-plain Vendelinus
A, which has a prominently terraced wall and a large bright central
mountain. Between A and C extends a plateau that may be regarded as the
N. limit of the formation, including, among other minor details, a fine
cleft, which traverses it from N. to S., and ultimately extends to a
group of craters on the floor. On the S. side of the interior is one
large ring-plain, flanked on the W. by two small craters. Near the N. end
are many bright little craters, many of them unrecorded. Vendelinus C is
bordered on the E. by two large semicircular formations with low walls
extending on to the floor. Mr. W.H. Maw and others have detected many
minute depressions in connection with these curious objects; and N. of
them, on the outer slope of C, where it runs out to the level of the
plateau, I have seen the surface at sunset riddled like a sieve with
craterlets and little pits. There is an irregular ring-plain N. of A,
with linear walls, and another, much smaller and brighter, on the N. of
this, standing a little beyond the N. limits of Langrenus.
LA PEYROUSE.--A much foreshortened walled-plain, 41 miles in diameter,
close to the limb, S.W. of Langrenus. There is a longitudinal ridge on
the floor. Between it and Langrenus are two large ring-plains with
central mountains, and on the N.E., La Peyrouse A, a bright crater,
adjoining which is La Peyrouse DELTA, one of the most brilliant spots on
the moon.
ANSGARIUS.--A ring-plain, 50 miles in diameter, still nearer to the limb
than the last.
BEHAIM.--A great ring-plain, 65 miles in diameter, S. of Ansgarius, and
connected with it by ridges. It has lofty walls and a central mountain.
HECATAEUS.--An immense walled-plain, 115 miles in length, on the S.W. of
Vendelinus, with a very irregular rampart and a conspicuous central
mountain. It is flanked E. and W. by other large enclosures, which can
only be seen to advantage when libration is favourable.
W. HUMBOLDT.--Though close to the limb, this enormous wall-surrounded
plain, some 130 miles in extreme length, and estimated to have an area of
12,000 square miles, is well worth observing under suitable conditions.
It ranks among the largest formations of its class, and in many respects
resembles Bailly on the S.E. limb. At one point on the E. a peak rises to
16,000 feet, and on the opposite side there are peaks nearly as high. The
floor contains some detail--a crater, nearly central, associated with
ridges, and two dark spots, one at the S. and the other at the N. end.
PHILLIPS.--Abuts on the E. side of W. Humboldt. It is a walled-plain,
about 80 miles in length, with a border much broken on the E., and
terraced within on the opposite side. There are many hills and ridges on
the floor.
LEGENDRE.--A fine ring-plain, 46 miles in diameter, on the S.E. of the
last. According to Schmidt, there is a crater on the S. side of the
floor. There is a small ring-plain, ADAMS, on the S.
PETAVIUS.--The third member of the great meridional chain: a noble
walled-plain, with a complex rampart, extending nearly 100 miles from N.
to S., which encloses a very rugged convex floor, traversed by many
shallow valleys, and includes a massive central mountain and one of the
most remarkable clefts on the visible surface. To observe these features
to the best advantage, the formation should be viewed when its W. wall is
on the evening terminator. At this phase a considerable portion of the
interior on the N. is obscured by the shadow of the rampart, but the
principal features on the S. half of the floor, and on the broad gently-
shelving slope of the W. wall, are seen better than under any other
conditions. The border is loftiest on the E., where the ring-plain
Wrottesley abuts on it. It rises at this point to nearly 11,000 feet,
while on the opposite side it nowhere greatly exceeds 6000 feet above the
interior. The terraces, however, on the W. are much more numerous, and,
with the associated valleys, render this section of the wall one of the
most striking objects of its class. The N. border is conspicuously broken
by the many valleys from the region S. of Vendelinus, which run up to and
traverse it. On the S., also, it is intersected by gaps, and in one place
interrupted by a large crater. There is a remarkable bifurcation of the
border S. of Wrottesley. A lower section separates from the main rampart
and, extending to a considerable distance S.E. of it, encloses a wide and
comparatively level area which is crossed by two short clefts. The
central mountains of Petavius, rising at one peak to a height of nearly
6000 feet above the floor, form a noble group, exceeding in height those
in Gassendi by more than 2000 feet. The convexity of the interior is such
that the centre of it is about 800 feet higher than the margin, under the
walls; a protuberance which would, nevertheless, be scarcely remarked _in
situ_, as it represents no steeper gradient than about 1 in 300 on any
portion of its superficies. The great cleft, extending from the central
mountains to the S.E. wall, and perhaps beyond, was discovered by
Schroter on September 16, 1788, and can be seen in a 2 inch achromatic.
In larger instruments it is found to be in places bordered by raised
banks.
WROTTESLEY.--A formation, about 25 miles in diameter, closely associated
with the E. wall of Petavius, the shape of which it has clearly modified.
Its border on the E., of the linear type, rises nearly 9000 feet above a
light interior, where there is a small bright central mountain and some
mounds. There is a prominent valley running along the inner slope of the
W. wall.
PALITZSCH.--If this extraordinary formation is observed when the moon is
about three days old, it resembles a great trough, or deep elongated
gorge flanking the W. wall of Petavius, though it is a true ring-plain,
albeit of a very abnormal type, about 60 miles in length and 20 miles in
breadth, with a somewhat dusky interior. On the outer slope of its W.
wall is a bright ring-plain with a lofty border and a central mountain.
HASE.--An irregular formation, about 50 miles in diameter, on the S.W. of
Petavius, with which it is connected by extensions of the W. and E. walls
of the latter. Its rampart, some 7000 feet above the floor, is broken by
depressions on the W.; and on the S. is bounded by a smaller ring-plain
with still loftier walls. Schmidt shows a large crater and three smaller
ones on the W. side of the floor.
MARINUS.--A ring-plain on the N.E. side of the Mare Australe, between
Furnerius and the limb.
FURNERIUS.--The fourth and most southerly component of the great
meridional chain of walled-plains, commencing on the N. with Langrenus: a
fine but irregular enclosure, about 80 miles in extreme length and much
more in breadth. Its rampart is very lofty, and tolerably continuous on
the N. and W., but on the other sides is interrupted by small craters and
depressions. At peaks on the E. it attains a height of more than 11,000
feet above the interior, and there are other peaks rising nearly as high.
There is a ring-plain (Furnerius B) with a central hill, on the E. side
of the floor, and numerous craters and crater-pits in other parts of it.
On the N.W. side of B there is a short cleft, on the W., a well-marked
crater-row, and on the E. a long rill-valley. The very brilliant crater
(Furnerius A) on the N.E. _glacis_ is the origin of two fine light
streaks, one extending S. for more than 100 miles, and the other in the
opposite direction for a great distance.
FRAUNHOFER.--A ring-plain, S. of Furnerius, about 30 miles in diameter,
with a regular border rising about 5000 feet above the floor. A smaller
ring-plain abuts on the N.E. side of it, which has slightly disturbed its
wall.
OKEN.--A large enclosure in S. lat. 43 deg. with broken irregular walls.
It is too near the limb for observation.
VEGA.--Schmidt represents this peculiar formation, situated S.E. of Oken,
as having a regular curved unbroken rampart on the E., while the opposite
border is occupied by four large partially overlapping ring-plains, two
of which contain small craters. The floor is devoid of detail.
PONTECOULANT.--A great irregular walled plain, about 100 miles in length,
near the S.W. limb, with a border rising in places to a height of 6000
feet above the floor.
HANNO.--A smaller and more regular enclosure, adjoining Pontecoulant on
the N.W., and still nearer the limb.
WEST LONGITUDE 60 deg. TO 40 deg.
MESSIER.--The more westerly of a remarkable pair of bright craters, about
9 miles in diameter, standing in an isolated position in the Mare
Foecunditatis just S. of the Equator. Madler represents them as similar
in every respect, but Webb, observing them in 1855 and 1856 with a 3 7/10
achromatic, found them very distinctly different,--Messier, the more
westerly, being not only clearly smaller than its companion, but longer
from W. to E. than from N. to S., as it undoubtedly is at the present
time. Messier A, however, as the companion is termed, though larger, is
certainly not circular, as sometimes shown, but triangular with curved
sides. It is just possible that change may have occurred here, for Madler
carefully observed these objects more than three hundred times, and, it
may be presumed, under very different phases. Messier A is the origin of
two slightly divergent light streaks, resembling a comet's tail, which
extend over the Mare towards its E. border N. of Lubbock, and are crossed
obliquely by a narrower streak. Messier and Messier A stand near the S.
and narrowest end of a tapering curved light area. There is a number of
craterlets and minute pits in the neighbourhood, and under a high light
two round dusky spots are traceable in connection with the "comet"
marking, one just beyond its northern, and the other beyond its southern
border, near its E. extremity.
LUBBOCK.--A brilliant little crater, about 4 or 5 miles in diameter, near
the E. coast-line of the Mare Foecunditatis. The region E. of this object
is particularly well worthy of scrutiny under a low sun, on account of
the variety of detail it includes. On the S.E. run three fine parallel
clefts, originating near the N. end of the Pyrenees.
GUTTEMBERG.--A very fine ring-plain of peculiar shape, about 45 miles in
width, with a lofty wall, broken on the N.W. by another ring-plain some
14 miles in diameter, and on the S.E. by a small but distinct crater. The
border presents a wide opening towards the S., which is traversed by a
number of longitudinal valleys, both the E. and W. sections of the wall
being prolonged in this direction. A fine crater-row runs round the outer
slope of the E. wall, from the crater just mentioned to the N. side of
the formation. It is best seen when the W. wall is on the evening
terminator. There is also a broad valley on the S. prolongation of the W.
wall. The central mountain is bright but not large. A cleft crosses the
N.W. side of the floor. North of Guttemberg there is a curious oblong
formation with low walls, connected with the N.E. border by a ridge, and
with the N. border by a remarkable row of depressions, situated on a
mound; and beyond this object on the E. are three parallel clefts running
towards the N.E. On the W. will be found some of the clefts belonging to
the Goclenius rill-system. In the rugged region S.E. of the formation is
a peculiar low ring with a very uneven floor and a large central hill.
The E. wall of Guttemberg may be regarded as forming a portion of the
Pyrenees Mountains.
GOCLENIUS.--A ring-plain, about 28 miles in diameter, bearing much
resemblance to Plinius in form and size, and, like this formation,
associated with a fine system of clefts. The lofty rampart, tolerably
continuous on the W., is broken on the S.W. by a bright crater, and on
the N.W. by a remarkable triangular depression. It is also traversed by a
delicate valley extending from the crater on the S.W. to another on the
N.W. border; and at a point a little W. of the first crater is dislocated
by an intrusive mass of rock. There are several gaps on the E. and many
spurs and irregularities in outline both within and without. A great
portion of the N. wall is linear, and joins the E. section nearly at
right angles. West of the triangular depression it appears to be
partially wrecked, indications of the destruction being very evident if
it be observed when the E. wall is near the morning terminator. The small
bright central mountain is remarkable for its curious oblong shadow. Two
clefts traverse the interior of Goclenius. (1) Originates at the S. wall,
E. of the crater, and runs E. of the central mountain to the N. wall; (2)
crosses the _debris_ of the ruined N.W. border, runs parallel to the
first, and extends nearly to the centre of the floor, (1) Re-appears at
the foot of a mound outside the N. wall, and, after crossing the outer W.
slope of the great ring-plain on the N.W. wall of Guttemberg, runs to the
W. side of an oblong formation N. of it. There are two other clefts,
closely parallel and W. of this, traversing the Mare, and terminating
among the mountains on the N.W. These are crossed at right angles by what
appears to be a "fault," running in a N.W. direction from the W. side of
Guttemberg.
MACCLURE.--One of a curious group of formations situated in the Mare
Foecunditatis some distance S.W. of Goclenius. It is a bright ring-plain,
about 15 miles in diameter, with a narrow gap in the N.E. wall and a
small central hill. A prominent ridge runs up to the N. border; and on
the S.W. a rill-valley may be traced, extending S. to a bright deep
little crater W. of Cook.
CROZIER.--A conspicuous ring-plain a few miles N.N.W. of MacClure, and of
about the same size. It has a faint central hill. Neison refers to two
long straight streaks extending from Crozier towards Messier.
BELLOT.--A brilliant little ring-plain N.E. of Crozier.
COOK.--A ring-plain, about 25 miles in diameter, on the E. side of the
Mare Foecunditatis in S. lat. 17 deg., with low and (except on the S.E.)
very narrow walls. There is a small circular depression on the S. border,
and a prominent crater on the W. side of the dark interior. On the S.S.E.
is the curiously shaped enclosure Cook _d_, with very bright broad lofty
walls and a fine central mountain. On the plain W. of Cook is a
conspicuous crater-row, consisting of six or seven craters, diminishing
in size in both directions from the centre.
COLOMBO.--A fine ring-plain, about 50 miles in diameter, situated in the
highlands separating the Mare Foecunditatis and the Mare Nectaris. The
wall, rising at one place to a height of 8000 feet above the floor, is
very complicated and irregular, being traversed within by many terraces,
and almost everywhere by cross-valleys. Its shape is greatly distorted by
the large ring-plain _a_, which abuts on its N.E. flank. It loses its
individuality altogether on the S., its place being occupied by two large
depressions, and lofty mountains trending towards the S.E. In the centre
there are several distinct bright elevations.
MAGELHAENS.--The more northerly and the larger of a pair of ring-plains
between Colombo and Goclenius, with a bright and somewhat irregular
though continuous border. The dark interior includes a small central
mountain. Its companion on the S.W., Magelhaens _a_, slightly overlaps
it. This also has a central hill, and a crater on the outer slope of its
E. wall.
SANTBECH.--A very prominent ring-plain, 46 miles in diameter, on the S.E.
side of the Mare Foecunditatis, W. of Fracastorius. The continuity of its
fine lofty rampart is broken on the W., where it rises nearly 10,000 feet
above the floor, by a brilliant little crater just below the crest, and
by a narrow gap on the S. The wall on the E. towers to a height of 15,000
feet above the interior. On its broad outer slope, near the summit, there
is a fine crater, and S. of this running obliquely down the slope a
distinct valley. On the N.E., where the _glacis_ runs down to the level
of the surrounding plain, there is a large crateriform object with a
broken N. border, and a small crater opposite the opening. A long coarse
valley runs from this latter object in a N.E. direction to the region W.
of Bohnenberger. Santbech contains a prominent central peak.
BIOT.--A brilliant little ring-plain, scarcely more than 7 miles in
diameter, standing in an isolated position in the Mare Foecunditatis N.E.
of Wrottesley. There is a number of bright streaks in its neighbourhood;
and a few miles E. of it, in the hilly region W. of Santbech, another
conspicuous crater of about the same size.
BORDA.--A ring-plain about 25 miles in diameter, S.S.W. of Santbech, with
a rampart low on the N. and S., but elsewhere of considerable height, and
a very conspicuous central mountain. A wide deep valley flanked by lofty
mountains extends from the N. wall for many miles towards the N.W. It is
an especially noteworthy object when the W. wall of Santbech is on the
evening terminator, as its somewhat winding course, indicated by the
bright summit-ridges of the bordering mountains, can be followed some
hours before either the interior of the valley or the region between it
and Santbech are in sunlight. Among the mountains W. of Borda there is a
peak more than 11,000 feet in height.
SNELLIUS.--A very fine ring-plain, 50 miles in diameter, S.E. of
Petavius, with terraced walls, considerably broken on the S.E. by
craters, &c. It rises on the E. nearly 7000 feet above a dark floor,
which contains a central mountain. N.E. of Snellius is a smaller ring-
plain (Snellius _a_), and due E. a curious rough plateau, bordered on the
N. and S. by a number of small craters.
STEVINUS.--A somewhat larger ring-plain, S. of Snellius, with a border
rising on the S. to more than 11,000 feet above a dark interior, which
includes a bright central mountain.
REICHENBACH.--A very abnormally-shaped ring-plain, about 30 miles in
diameter, with a rampart nearly 12,000 feet high. The border is broken on
the W., S., and E. by craters and depressions, and on the N. is flanked
by two overlapping ring-plains, _a_ and _b_. On the S.W. lies a
magnificent serpentine valley, fully 100 miles in length and about 12
miles in breadth at the N. end, but gradually diminishing as it runs
southwards, till it reaches a depression N. of Rheita, where it
terminates: here is scarcely more than 4 miles wide.
RHEITA.--A formation, about 35 miles in diameter, S. of Reichenbach, with
regular lofty walls, rising at a peak on the N.E. to a height of more
than 14,000 feet above the interior, on which there is a small but
prominent central mountain, a smaller elevation W. of the centre, and two
adjoining craters at the foot of the S. wall. On the E. originates
another fine valley, very similar to that already mentioned in connection
with Reichenbach. It runs in a S.S.W. direction, is about 100 miles in
length, and, in its widest part, is about 12 miles across. Like the
Reichenbach valley, it terminates at a small crater-like object, which
has a border broken down on the side facing the valley, and a small
central hill. About midway between its extremities, this great gorge is
crossed by a wall of rock, like a narrow bridge.
JANSSEN.--An immense irregular enclosure, reminding one of the very
similar area, bordered by Walter, Lexell, Hell, &c., in the third
quadrant. It extends about 150 miles from E. to W., and more than 100
from N. to S., its limits on the N. being rather indefinite. Its very
rugged humpy surface includes one great central mountain, and innumerable
minor hills and ridges, craters, and crater-pits; but the principal
feature is the magnificent curved rill-valley running from the S. side of
Fabricius across the rough expanse to the S. side. This fine object, very
coarse on the N., passes the central mountain on the E. side, and becomes
gradually narrower as it approaches the border; before reaching which,
another finer cleft branches from it on the W., and also runs to the S.
side of the plain.
LOCKYER.--A prominent deep ring-plain, 32 miles in diameter, with massive
bright lofty walls, standing just outside the S.E. border of Janssen.
Schmidt shows a minute crater on the S. rim. I have seen a crater within,
at the inner foot of the W. wall, and a central peak.
FABRICIUS.--A ring-plain, 55 miles in diameter, with a lofty terraced
border, rising on the S.W. to a height of nearly 10,000 feet above the
interior. It is partially included by the rampart of Janssen, and the
great rill-valley on the floor of the latter appears to cut through its
S. wall. There is a long central mountain on the floor, with a prominent
ridge extending along the E. side of it. W. of Fabricius (between it and
the border of Janssen) lies a very irregular enclosure, with three
distinct craters within it; and on the E., running from the wall to the
E. side of Janssen, is a straight narrow valley. Both Fabricius and
Janssen should be viewed under a low morning sun.
STEINHEIL.--A double ring-plain, W. of Janssen, 27 miles in diameter. The
more easterly formation sinks to a depth of nearly 12,000 feet below the
summit of the border.
METIUS.--This ring-plain, of about the same size as Fabricius, but with a
still loftier barrier, abuts on the N. wall of this formation, and has
caused a very obvious deformation in its contour. It is prominently
terraced internally, and on the W. the wall rises at one peak to a height
of 13,000 feet above the floor, which contains a deep crater on the W. of
the centre, and many ridges.
BIELA.--A considerable ring-plain, about 55 miles in diameter, S.W. of
Janssen, with a wall broken on the N.W., S., and E. by rings and large
enclosures. There is a central mountain, but apparently no other details
on the floor.
ROSENBERGER.--This formation, about 50 miles in diameter, is one of the
remarkable group of large rings to which Vlacq, Hommel, Pitiscus, &c.,
belong. Its walls, though of only moderate altitude, are distinctly
terraced. In addition to a prominent central mountain (E. of which
Schmidt shows two craters), there is a large crater on the S. side of the
floor, and many smaller craters and crater-pits.
HAGECIUS.--The most westerly member of the Vlacq group of formations. It
is situated on the S.W. of Rosenberger, and is about 50 miles in
diameter. The rampart on the E. is continuous and of the normal type, but
on the opposite side is broken by a number of smaller rings.
WEST LONGITUDE 40 deg. TO 20 deg.
CENSORINUS.--A brilliant little crater, with very bright surroundings, in
the Mare Tranquilitatis, nearly on the moon's equator, in W. long. 32
deg. 22 min. Another smaller but less conspicuous crater adjoins it on
the W. On the Mare to the S. extends a delicate cleft which trends
towards the Sabine and Ritter rill system.
CAPELLA.--Forms with Isodorus, its companion on the E. (which it
partially overlaps), a very noteworthy object. It is about 30 miles in
diameter, with finely terraced walls, broken on the S.W. by broad
intrusive rill-valleys. The rampart on the N.E. is also cut through by a
magnificent valley, which extends for many miles beyond the limits of the
formation. There is a fine central mountain, on which M. Gaudibert
discovered a crater, the existence of which has been subsequently
verified by Professor Weinek on a Lick observatory negative.
ISODORUS.--The rampart of this fine ring-plain, which is of about the
same size as Capella, rises at a peak on the W. to a height of more than
13,000 feet above the interior, which, except a small bright crater at
the foot of the E. wall and a smaller one adjoining it on the N.,
contains no detail. The region between Isodorus and the equator includes
many interesting objects, among them Isodorus _b_, an irregular formation
open towards the N., and containing several craters.
BOHNENBERGER.--A ring-plain about 22 miles in diameter, situated on the
W. side of the Mare Nectaris, under the precipitous flanks of the
Pyrenees, whose prominent shadows partially conceal it for many hours
after sunrise. The circular border is comparatively low, and, except on
the N., continuous. Here there is a gap, and on the W. of it an intrusive
mass of rock. From its very peculiar shadow at sunrise, the wall on the
E. appears to be very irregular. The club-shaped central mountain is of
considerable size, but not conspicuous. S. of Bohnenberger stands the
very attenuated ring, Bohnenberger A. It is of about the same diameter,
has a large deep crater on its N. rim, and a smaller one, distinguished
with difficulty, on its S.E. rim. On the N. of Bohnenberger there is a
bright little ring-plain connected with the formation by a lofty ridge,
under the E. flank of which Schmidt shows a crater-chain. An especially
fine cleft originates on the E. side of this crater, which, following an
undulating course over the Mare Nectaris, terminates at Rosse, N. of
Fracastorius.
TORRICELLI.--A remarkable little formation in the Mare Tranquilitatis, N.
of Theophilus, consisting of two unequal contiguous craters ranging from
W. to E., whose partition wall has nearly disappeared, so that, under a
low sun, when the interior of both is filled with shadow, the pair
resemble the head of a javelin. The larger, western, ring is about 10
miles in diameter, and the other about half this size. There is a gap in
the W. wall of the first, and a long spur projecting from its S. side;
and a minute crater on the S. border of the smaller object. Torricelli is
partially enclosed on the S. by a circular arrangement of ridges. There
is a delicate cleft running in a meridional direction on the Mare, E. of
the formation, and another on the N., running from W. to E.
HYPATIA.--A ring-plain, about 30 miles in extreme length, of very
abnormal shape, on the E. side of the Mare, N.N.E. of Theophilus, with a
wall rising at a peak on the E. to a height of more than 7000 feet above
a dusky floor, which does not apparently contain any detail. A small
crater breaks the uniformity of the border on the W. Beyond the wall on
the S.E. lies the fine bright crater Hypatia A, with another less
prominent adjoining it on the S.W.
THEOPHILUS.--The most northerly of three of the noblest ring-mountains on
the visible surface of the moon, situated on the N.E. side of the Mare
Nectaris. It is nearly 64 miles in diameter, and is enclosed by a mighty
rampart towering above the floor at one peak on the W. to the height of
18,000 feet, and at two other peaks on the opposite side to nearly 16,000
and 14,000. The border, though appearing nearly circular with low powers,
is seen, under greater magnification, to be made up of several more or
less linear sections, which give it a polygonal outline. It is
prominently terraced within, the loftier terraces on the W. rising nearly
to the height of the crest of the wall, and including several craters and
elongated depressions. On the W. _glacis_ is a row of large inosculating
craters; and near its foot, S.E. of Madler, a short unrecorded rill-
valley. The magnificent bright central mountain is composed of many
distinct masses surmounted by lofty peaks, one of which is about 6000
feet above the floor, and covers an area of at least 300 square miles.
Except a distinct crater on the S.W. quarter, this appears to be the only
object within the ring.
CYRILLUS.--The massive border of Theophilus partially overlaps the N.W.
side of this great walled-plain, which is even more complex than that of
its neighbour, and far more irregular in form, exhibiting many linear
sections. Its crest on the S.E. is clearly inflected towards the
interior, a peculiarity that has already been noticed in connection with
Copernicus and some other objects. On the inner slope of this wall there
is a large bright crater, in connection with which have been detected two
delicate rills extending to the summit. I have not seen these, but one of
the crater-rows shown by Schmidt, between this crater and the crest, has
often been noted. The N.E. wall is very remarkable. It appears to be
partially wrecked. If observed at an early stage of sunrise, a great
number of undulating ridges and rows of hillocks will be seen crossing
the region E. of Theophilus. They resemble a consolidated stream of
"ropy" lava which has flowed through and over the wall and down the
_glacis_. The arrangement of the ridges within Cyrillus is very
noteworthy, as is also the triple mountain near the centre of the floor.
The fine curved cleft thereon traverses the W. side, sweeping round the
central mountains, and then turning to the south. I have only
occasionally seen it in its entirety. There are also two oblong dark
patches on the S. side of the interior. The S. wall of Cyrillus is broken
by a narrow pass opening out into a valley situated on the plateau which
bounds the W. side of the oblong formation lying between it and
Catherina, and overlooking a curious shallow square-shaped enclosure
abutting on the S.W. side of Cyrillus.
CATHERINA.--The largest of the three great formations: a ring-plain with
a very irregular outline, extending more than 70 miles in a meridional
direction, and of still greater width. The wall is comparatively narrow
and low on the N.E. (8000 feet above the floor), but on the N.W. it rises
to more than double this height, and is broken by some large depressions.
The inner slope on the S.E. is very gentle, and includes two bright
craters, but exhibits only slight indications of terraces. The most
remarkable features on an otherwise even interior are the large low
narrow ring (with a crater within it), occupying fully a third of the
area of the floor, and a large ring-plain on the S. side.
MADLER.--The interest attaching to this formation is not to be measured
by its size, for it is only about 20 miles in diameter, but by the
remarkable character of its surroundings. Its bright regular wall, rising
6000 feet on the E. and only about half as much on the W., above a rather
dark interior, is everywhere continuous, except at one place on the N.
Here there is a narrow gap (flanked on the E. by a somewhat obscure
little crater) through which a curious bent ridge coming up from the N.
passes, and, extending on to the floor, expands into something resembling
a central mountain. Under a high sun Madler has a very peculiar
appearance. The lofty E. wall is barely perceptible, while the much lower
W. border is conspicuously brilliant; and the E. half of the floor is
dark, while the remainder, with two objects representing the loftier
portions of the intrusive ridge, is prominently white. Under an evening
sun, with the terminator lying some distance to the W., a very remarkable
obscure ring with a low border, a valley running round it on the W. side,
and two large central mounds, may be easily traced. This object is
connected with Madler by what appears to be under a higher sun a bright
elbow-shaped marking, in connection with which I have often suspected a
delicate cleft. Between the obtuse-angled bend of this object and the W.
wall of Madler, two large circular dark spots may be seen under a high
sun; and on the surface of the Mare N. of it, a great number of delicate
white spots.
BEAUMONT.--A ring-plain about 30 miles in diameter, on the S.E. side of
the Mare Nectaris, midway between Theophilus and Fracastorius, with the
N.E. side of which it is connected by a chain of large depressions. Its
border is lofty, regular, and continuous on the S. and E., but on the W.
it is low, and on the N. sinks to such a very inconsiderable height that
it is often scarcely traceable. It exhibits two breaks on the S.W.,
through one of which passes a coarse valley that ultimately runs on the
E. side of the depressions just referred to. The interior is pitted with
many craters, one on the W. side being shallow but of considerable size.
I once counted twenty with a 4 inch Cooke achromatic, and Dr. Sheldon of
Macclesfield subsequently noted many more. A ridge, prominent under
oblique light, follows a winding course from the N.W. side of Beaumont to
the W. side of Theophilus, and there is another lower ridge E. of it.
Between them is included a region covered with minute hillocks and
asperities. Among these objects are certain dusky little crater-cones,
which Dr. Klein of Cologne regards as true analogues of some terrestrial
volcanoes. They are very similar in character to those, already alluded
to, in the dusky area between Copernicus and Gambart.
KANT.--A conspicuous ring-plain, 23 miles in diameter, situated in a
mountainous district E. of Theophilus, with lofty terraced walls and a
bright central peak. Adjoining it on the W. is a mountain mass,
projecting from the coast-line of the Mare, on which there is a peak
rising to more than 14,000 feet above the surface.
FRACASTORIUS.--This great bay or inflexion at the extreme S. end of the
Mare Nectaris, about 60 miles in diameter, is one of the largest and most
suggestive examples of a partially destroyed formation to be found on the
visible surface. The W. section of the rampart is practically complete
and unbroken, rising at one peak to a height of 6000 feet above the
interior. It is very broad at its S. end, and its inner slope descends
with a gentle gradient to the floor. Towards the N., however, it rapidly
decreases in width, but apparently not in altitude, till near its bright
pointed N. extremity. Under a low sun, some long deformed crateriform
depressions may be seen on the slope, and a bright little crater on the
crest of the border near its N. end. The southern rampart is broken by
three large craters, and a fine valley, running some distance in a S.
direction, which diminishes gradually in width till it ultimately
resembles a cleft, and terminates at a small crater. The E. border is
very lofty and irregular, rising at the N. corner of the large triangular
formation, which is such a prominent feature upon it, to a height of 7000
feet, and at a point on the S.E. to considerably more than 8000 feet
above the floor. N. of the former peak it becomes much lower and
narrower, and is finally only represented by a very attenuated strip of
wall, hardly more prominent than the brighter portions of the border of
Stadius at sunrise, terminating at an obscure semi-ring-plain. Between
this and the pointed N. termination of the W. border there is a wide gap,
open to the north for a space of about 30 miles, appearing, except under
very oblique illumination, as smooth and as devoid of detail as the grey
surface of the Mare Nectaris itself. If, however, this interval is
observed at sunrise or sunset, it is seen to be not quite so
structureless as it appears under different conditions, for a number of
mounds and large humpy swellings, with low hills and craterlets, extend
across it, and occupy a position which we are justified in regarding as
the site of a section of the rampart, which, from some cause or other,
has been completely destroyed and overlaid with the material, whatever
this may be, of the Mare Nectaris. The floor of Fracastorius is, as
regards the light streaks and other features upon it, only second in
interest to those of Plato and Archimedes, and will repay systematic
observation. Between thirty and forty light spots and craters have been
recorded on its surface, most of them, as in these formations, being
situated either on or at the edges of the light streaks. On the higher
portion of the interior (near the centre) is a curious object consisting
apparently of four light spots, arranged in a square, with a craterlet in
the middle, all of which undergo (as I have pointed out elsewhere)
notable changes of aspect under different phases. There are at least two
distinct clefts on the floor, one running from the W. wall towards the
centre, and another on the S.E. side of the interior. The last throws out
two branches towards the S.W.
ROSSE.--A fine bright deep crater in the Mare Nectaris, N. of the pointed
termination of the W. wall of Fracastorius, with which it is connected by
a bold curved ridge, with a crater upon it. A ray from Tycho, striking
along the E. wall of Fracastorius passes near this object. A rill from
near Bohnenberger terminates at this crater.
POLYBIUS.--A ring-plain, about 17 miles in diameter, in the hilly region
S.E. of Fracastorius. The border is unbroken, except on the N., where it
is interrupted by a group of depressions. There is a long valley on the
S.W., at the bottom of which Schmidt shows a crater-chain.
NEANDER.--This ring-plain, 34 miles in diameter, a short distance W.S.W.
of Piccolomini, has a somewhat deformed rampart, which, however, except
on the N., where there is a narrow gap occupied by a small crater, is
continuous. It rises on the E. nearly 8000 feet above the floor, on which
there is a central mountain about 2500 feet high. Schmidt shows some
minor hills, a large crater on the N.E. side, and three smaller craters
in the interior.
PICCOLOMINI.--A ring-plain of a very massive type, about 57 miles in
diameter, S. of Fracastorius, with complex and prominently terraced
walls, surmounted by very many peaks; one of which on the E. attains a
height of 14,000 feet, and another, N. of it, on the same side, an
altitude of 15,000 feet above the interior. The crest of this grand
rampart is tolerably continuous, except on the S.W., where, for a
distance of twenty miles or more, its character as regards form and
brightness is entirely changed. Under a low sun, instead of a continuous
bright border, we note a wide gap occupied by a dusky rugged plateau,
which falls with a gentle gradient to the floor, and is traversed by
three or four parallel shallow valleys running towards the S. I can
recall no lunar formation which presents an appearance at all like this:
one is impressed with the idea that it has resulted from the collapse of
the upper portion of the wall, and the flow of some viscous material over
the wreck and down the inner slope. The difference between the reflective
power of this matter, whatever may be its nature, and the broad bright
declivities of the inner slopes, are beautifully displayed at sunset. The
cross-valleys are more easily traced under low morning illumination; but
to appreciate the actual structure of the wall, it should be observed
under both phases. The N.W. section of the border includes many
"pockets," or long elliptical depressions, which at an early stage of
sunrise give a scalloped appearance to the crest. Except the great bright
central mountain with its numerous peaks, there does not appear to be any
prominent detail on the floor. There is a large ring-plain beyond the
foot of the _glacis_ on the W. with two craters on the E. side of it,
another on the S., and a fine rill-valley running up to its N. side from
near the crest of the W. wall. On the N. side of Piccolomini is a
remarkable group of deformed and overlapping enclosures, mingled with
numberless craters and little depressions. The plain on the N.E. is
crossed by a fine cleft.
PONS.--A complete formation of irregular shape, about 20 miles in
greatest diameter, on the S.E. side of the Altai range, in W. long. 21
deg. It consists of a crowd of rings and craters enclosed by a narrow
wall.
STIBORIUS.--An elongated ring-plain, about 22 miles in diameter, S. of
Piccolomini, with a lofty wall, broken in one place on the N. by a very
conspicuous crater. Schmidt shows a distinct crater in the centre of the
floor. I have only seen a central mountain in this position. There is a
large crater on the N.W., a ring-plain on the S.W. side, and a multitude
of little craters on the surrounding plain.
RICCIUS.--A ring-plain, 51 miles in diameter, of a very irregular type,
S.E. of the last. It is enclosed by a complex wall (which is in places
double), broken by large rings on the S. The very conspicuous little
ring-plain Riccius A is situated on the N. of it, and other less
prominent features. The interior includes a bright crater and some
smaller objects of the same class.
ZAGUT.--The most easterly of a group of closely associated irregular
walled-plains, of which Lindenau and Rabbi Levi are the other members,
all evidently deformed and modified in shape by their proximity. It is
about 45 miles in diameter, and is enclosed by a wall which on the S.W.
attains a height of about 9500 feet, and is much broken on the N. by a
number of depressions. A large ring-plain, some 20 miles in diameter,
occupies a considerable portion of the W. side of the interior; E. of
which, and nearly central, there is a large bright crater, but apparently
no other conspicuous details. On the S.E. side of Zagut lies an
elliptical ring-plain, about 28 miles in diameter, named by Schmidt
CELSIUS. The border of this is open on the N., the gap being occupied by
a large crater, whose S. wall is wanting, so that the interiors of both
formations are in communication.
LINDENAU.--This formation, about 35 miles in diameter, is bounded on the
W. by a regular unbroken wall nearly 8600 feet in height; but which on
the E. and N.E. is far loftier and more complex, rising to about 12,000
feet above the floor, consisting of four or more distinct ramparts,
separated by deep valleys, and extending towards Rabbi Levi. Neison
points out that under a high light Lindenau appears to have a bright
uniform single wall. There is a small central mountain and some minor
inequalities in the interior.
RABBI LEVI.--A larger but less obvious formation than either of its
neighbours, Zagut and Lindenau, abutting on the S. side of them. It is
about 55 miles in diameter, and is enclosed by a border somewhat
difficult to trace in its entirety, except under oblique light. There are
some large craters within it, of which one on the N. side of the floor is
especially prominent.
NICOLAI.--A tolerably regular ring-plain, 18 miles in diameter, S. of
Riccius, with a border, rising more than 6000 feet above a level floor,
on the N. side of which Schmidt shows a minute crater. The bright plain
surrounding this formation abounds in small craters; and on the W. is a
number of curious enclosures, many of them overlapping.
VLACQ.--A member of a magnificent group of closely associated formations
situated on the greatly disturbed area between W. long. 30 deg. and 45
deg. and S. lat. 50 deg. and 60 deg. It is 57 miles in diameter, and is
enclosed by terraced walls, rising on the W. about 8000 feet, and on the
E. more than 10,000 feet above the floor. They are broken on the S. by a
fine crater. In addition to a conspicuous central peak, there are several
small craters, and low short ridges in the interior.
HOMMEL.--Adjoins Vlacq on the S. It is a somewhat larger and a far more
irregular formation. On every side except the W., where the border is
unbroken, and descends with a gentle slope to the dark interior; ring-
plains and smaller depressions encroach on its outline, perhaps the most
remarkable being Hommel _a_ on the N., which has an especially brilliant
wall, that includes a conspicuous central mountain, a large crater, and
other details. The best phase for observing Hommel and its surroundings
is when the W. wall is just within the evening terminator.
PITISCUS.--The most regular of the Vlacq group. It is situated on the
N.E. of Hommel (a curious oblong-shaped enclosure, Hommel _h_, with a
very attenuated E. wall, and a large crater on a floor, standing at a
higher level than that of Pitiscus, intervening). It is 52 miles in
diameter, and is surrounded by an apparently continuous rampart, except
on the E., where there is a crater, and on the S.W., where it abuts on
Hommel _h_. Here there is a wide gap crossed by what has every appearance
of being a "fault," resembling that in Phocylides on a smaller scale.
There is a fine crater on the N. side of the interior connected with the
S. wall by a bright ridge. Just beyond the E. border there is a shallow
ring-plain of a very extraordinary shape.
NEARCH.--A ring-plain, about 35 miles in diameter, on the S.W. of Hommel,
forming part of the Vlacq group.
TANNERUS.--A ring-plain, about 19 miles in diameter, between Mutus and
Bacon. It has a central mountain.
MUTUS.--A fine but foreshortened walled plain, 51 miles in diameter.
There are two ring-plains of about equal size on the floor, one on the
N., and the other on the S. side. The wall on the W. rises to nearly
14,000 feet above the interior.
MANZINUS.--A walled plain, nearly 62 miles in diameter, with a terraced
rampart rising to a height of more than 14,500 feet above the interior.
Schmidt shows three craterlets on the floor, but no traces of the small
central peak which is said to stand thereon, but to be only visible in
large telescopes.
SCHOMBERGER.--A large walled-plain adjoining Simpelius on the S.W. Too
near the limb for satisfactory observation.
WEST LONGITUDE 20 deg. TO 0 deg.
DELAMBRE.--A conspicuous ring-plain, 32 miles in diameter, a little S. of
the equator, in W. long. 17 deg. 30 min., with a massive polygonal
border, terraced within, rising on the W. to the great height of 15,000
feet above the interior, but to little more than half this on the
opposite side. Its outline approximates to that of a pentagon with
slightly curved sides. A section on the S.E. exhibits an inflexion
towards the centre. The crest is everywhere continuous except on the N.,
where it is broken by a deep crater with a bright rim. The north-easterly
trend of the ridges and hillocks on the E. is especially noteworthy. The
central peak is not prominent, but close under it on the E. is a deep
fissure, extending from near the centre, and dying out before it reaches
the S. border. At the foot of the N.E. _glacis_ there are traces of a
ring with low walls.
THEON, SEN.--A brilliant little ring-plain, E.N.E. of Delambre, 11 miles
in diameter, and of great depth, with a regular and perfectly unbroken
wall. North of it is a bright little crater.
THEON, JUN.--A ring-plain similar in size and in other respects to the
last, situated about 23 miles S. of it on a somewhat dusky surface.
Between the pair is a curious oblong-shaped mountain mass; and on the E.
a long cliff (of no great altitude, but falling steeply on the E. side)
extending S. towards Taylor _a_. Just below the escarpment, I find a
brilliant little pair of craterlets, of which Neison only shows one.
ALFRAGANUS.--A large bright crater, about 9 miles in diameter, with very
steep walls, some distance S.S.W. of Delambre, and standing on the W.
edge of a large but very shallow and irregular depression W. of Taylor.
There is a remarkable chain of craters on the W. of it. Alfraganus is the
centre of a system of light streaks radiating in all directions, one ray
extending through Cyrillus to Fracastorius.
TAYLOR.--A deep spindle-shaped ring-plain, S. of Delambre, about 22 miles
in length. The wall appears to be everywhere continuous, except at the
extreme N. and S. ends, where there are small craters. The outer slopes,
both on the E. and W., are very broad and prominent, but apparently not
terraced. There is an inconspicuous central hill. On the W. is the
irregular enclosure, already referred to under Alfraganus. Three or four
short winding valleys traverse the N. edge of this formation, and descend
to the dark floor. On the N.E. is the remarkable ring-plain Taylor _a_,
18 miles in diameter, rising, at an almost isolated mountain mass on the
E. border, to a height of 7000 feet above the interior. The more regular
and W. section of this formation is not so lofty, and falls with a gentle
slope to the dark uneven floor, on which there is some detail in the
shape of small bright ridges and mounds. On the surface, N.W. of Taylor
_a_, is a curious linear row of bright little hills. Taylor and the
vicinity is better seen under low evening illumination than under morning
light.
HIPPARCHUS.--Except under a low sun, this immense walled-plain is by no
means so striking an object as a glance at its representation on a chart
of the moon would lead one to expect; for the border, in nearly every
part of it, bears unmistakable evidence of wreck and ruin, its continuity
being interrupted by depressions, transverse valleys, and gaps, and it
nowhere attains a great altitude. This imperfect enclosure extends 97
miles from N. to S., and about 88 miles from E. to W., and in shape
approximates to that of a rhombus with curved sides. One of the most
prominent bright craters on its border is Hipparchus G, on the W.
Another, of about the same size, is Hipparchus E, on the N. of Horrocks.
On the E. there is a moderately bright crater, Hipparchus F; and S. of
this, on the same side, two others, K and I. The interior is crossed by
many ridges, and near the centre includes the relics of a low ring,
traversed by a narrow rill-like valley. Schmidt shows a cleft running
from F across the floor to the S. border.
[A valuable monograph of Hipparchus, by Mr. W.B. Birt, was published in
1870.]
HORROCKS.--This fine ring-plain, 18 miles in diameter, stands on the N.
side of the interior of Hipparchus, close to the border. It has a
continuous wall, rising on the E. to a height of nearly 8000 feet above
the interior, and a distinct central mountain.
HALLEY.--A ring-plain, 21 miles in diameter, on the S.W. border of
Hipparchus, with a bright wall, rising at one point on the E. to a height
of 7500 feet above the floor, which is depressed about 4000 feet below
the surface. Two craterlets on the floor, one discovered by Birt on
Rutherfurd's photogram of 1865, and the other by Gaudibert, raised a
suspicion of recent lunar activity within this ring. A magnificent
valley, shown in part by Schmidt as a crater-row, runs from the S. of
Halley to the W. side of Albategnius.
HIND.--A ring-plain, 16 miles in diameter, a few miles W. of Halley, with
a peak on its E. wall 10,000 feet above the floor. The border is broken
both on the S.E. and N.E. by small craters.
[Horrocks, Halley, and Hind may be regarded as strictly belonging to
Hipparchus.]
ALBATEGNIUS.--A magnificent walled-plain, 65 miles in diameter, adjoining
Hipparchus on the S., surrounded by a massive complex rampart,
prominently terraced, including many depressions, and crossed by several
valleys. It is surmounted by very lofty peaks, one of which on the N.E.
stands nearly 15,000 feet above the floor. The great ring-plain
Albategnius A, 28 miles in diameter, intrudes far within the limits of
the formation on the E., and its towering crest rises more than 10,000
feet above its floor, on which there is a small central mountain. The
central mountain of Albategnius is more than 4000 feet high, and, with
the exception of a few minor elevations, is the only prominent feature in
the interior, though there are many small craters. Schmidt counted forty
with the Berlin refractor, among them 12 on the E. side, arranged like a
string of pearls.
PARROT.--An irregularly-shaped formation, 41 miles in diameter, S. of
Albategnius, with a very discontinuous margin, interrupted on every side
by gaps and depressions, large and small; the most considerable of which
is the regular ring-plain Parrot _a_, on the E. An especially fine
valley, shown by Schmidt to consist in part of large inosculating
craters, cuts through the wall on the S.W., and runs on the E. side of
Argelander towards Airy. The floor of Parrot is very rugged.
DESCARTES.--This object, about 30 miles in diameter, situated N.W. of
Abulfeda, is bounded by ill-defined, broken, and comparatively low walls;
interrupted on the S.E. by a fine crater, Descartes A, and on the S.W. by
another, smaller. There is also a brilliant crater outside on the N.W.
Schmidt shows a crater-row on the floor, which I have seen as a cleft.
DOLLOND.--A bright crater, about 6 miles in diameter, on the N.E. side of
Descartes. Between it and the latter there is a rill-valley.
TACITUS.--A bright ring-plain, about 28 miles in diameter, a few miles E.
of Catherina, with a lofty wall rising both on the E. and W. to more than
11,000 feet above the floor. Its continuity is broken on the N. by a gap
occupied by a depression, and there is a conspicuous crater below the
crest on the S.W. The central mountain is connected with the N. wall by a
ridge, recalling the same arrangement within Madler. A range of lofty
hills, an offshoot of the Altai range, extends from Tacitus towards
Fermat.
ALMANON.--This ring-plain, with its companion Abulfeda on the N.E., is a
very interesting telescopic object. It is about 36 miles in diameter, and
is surrounded by an irregular border of polygonal shape, the greatest
altitude of which is about 6000 feet above the floor on the W. It is
slightly terraced, and is broken on the S. by a deep crater pertaining to
the bright and large formation Tacitus _b_, the E. border of which casts
a fine double-peaked shadow at sunrise. On the N.W. there is another
bright crater, the largest of the row, running in a W.S.W. direction, and
forming a W. extension of the remarkable crater-chain tangential to the
borders of Almanon and Abulfeda. The only objects on the floor are three
little hills, in a line, near the centre, a winding ridge on the W. side
of it, and two or three other low elevations.
ABULFEDA.--A larger and more massive formation than Almanon, 39 miles in
diameter, the E. wall rising about 10,000 feet above the interior, which
is depressed more than 3000 feet. It is continuous on the W., but much
broken by transverse valleys on the S.E., and by little depressions on
the N. On the S.E. originates the very curious bright crater-row which
runs in a straight line to the N.W. wall of Almanon, crossing for the
first few miles the lofty table-land lying on the S.E. side of the
border. With the exception of a low central mountain, the interior of
Abulfeda contains no visible detail. The rampart is finely terraced on
the E. and W. The E. _glacis_ is very rugged.
ARGELANDER.--This conspicuous ring-plain, about 20 miles in diameter, is,
if we except two smaller inosculating rings on the S.W. flank of
Albategnius, the most northerly of a remarkable serpentine chain of seven
moderately-sized formations, extending for nearly 180 miles from the S.W.
of Parrot to the N. side of Blanchinus. Its border is lofty, slightly
terraced within, and includes a central peak.
AIRY.--About 22 miles in diameter, connected with Argelander by a
depression bounded by linear walls. Its border, double on the S.E., is
broken on the S. by a prominent crater, with a smaller companion on the
W. of it; and again on the N.E. by another not so conspicuous. It has a
central peak. The next link in the chain of ring-plains is Airy _c_, a
very irregular object, somewhat larger, and with, for the most part,
linear walls.
DONATI.--A ring-plain on the S. of Airy _c_, about 22 miles in greatest
length. It is very irregular in outline, with a lofty broken border,
especially on the N. and S., where there are wide gaps. There is another
ring on the S.E.
FAYE.--The direction of the chain swerves considerably towards the E. at
this formation, which resembles Donati both in size and in irregularity
of outline. The wall, where it is not broken, is slightly terraced. There
is a craterlet on the S. rim and a central crater in the interior.
DELAUNAY.--Adjoins Faye on the S.E., and is a larger and more complex
object, of irregular form, with very lofty peaks on its border. A
prominent ridge of great height traverses the formation from N. to S.,
abutting on the W. border of Lacaille. Delaunay is the last link in the
chain commencing with Argelander.
LACAILLE.--An oblong enclosure situated on the N. side of Blanchinus, and
apparently about 30 miles in greatest diameter. The border is to a great
extent linear and continuous on the N., but elsewhere abounds in
depressions. Two large inosculating ring-plains are associated with the
N.E. wall.
BLANCHINUS.--A large walled-plain on the W. of Purbach and abutting on
the S. side of Lacaille. It much resembles Purbach in shape, but has
lower walls. Schmidt shows a crater on the N. side of the floor, which I
have seen, and a number of parallel ridges which have not been noted,
probably because they are only visible under very oblique light.
GEBER.--A bright ring-plain, 25 miles in diameter, S. of Almanon, with a
regular border, rising to a height on the W. of nearly 9000 feet above
the floor. There is a small crater on the crest of the S. wall, and
another on the N. A ring-plain about 8 miles in diameter adjoins the
formation on the N.E. According to Neison, there is a feeble central
hill, which, however, is not shown by Schmidt.
SACROBOSCO.--This is one of those extremely abnormal formations which are
almost peculiar to certain regions in the fourth quadrant. It is about 50
miles in greatest diameter, and is enclosed by a rampart of unequal
height, rising on the E. to 12,000 feet above the floor, but sinking in
places to a very moderate altitude. On the N. its contour is, if
possible, rendered still more irregular by the intrusion of a smaller
ring-plain. On the N.E. side of the floor stands a very bright little
crater and two others on the S. of the centre, each with central
mountains.
FERMAT.--An irregular ring-plain 25 miles in diameter on the W. of
Sacrobosco. Its partially terraced wall is broken on the N. by a gap
which communicates with the interior of a smaller formation. There are
some low hills on the floor, which is depressed 6000 feet below the crest
of the border.
AZOPHI.--A prominent ring-plain, 30 miles in diameter, E.N.E. of
Sacrobosco, its lofty barrier towering nearly 11,000 feet above a
somewhat dusky interior, which includes some light spots. A massive
curved mountain arm runs from the S. side of this formation to a small
ring-plain W. of Playfair.
ABENEZRA.--When observed near the morning terminator, this noteworthy
ring-plain, 27 miles in diameter, seems to be divided into two by a
curved ridge which traverses the formation from N. to S., and extends
beyond its limits. The irregular border rises on the W. to a height of
more than 14,000 feet above the deeply-sunken floor, which includes
several craters, hills, and ridges.
APIANUS.--A magnificent ring-plain, 38 miles in diameter, N.W. of
Aliacensis, with lofty terraced walls, rising on the N.E. to about 9000
feet above the interior, and crowned on the W. by three large conspicuous
craters. The border is broken on the N. by a smaller depression and a
large ring with low walls. The dark-grey floor appears to be devoid of
conspicuous detail.
PLAYFAIR.--A ring-plain, 28 miles in diameter, with massive walls. It is
situated on the N. of Apianus, and is connected with it by a mountain
arm. The rampart is tolerably continuous, but varies considerably in
altitude, rising on the S. to a height of more than 8000 feet above the
interior. On the E., extending towards Blanchinus, is a magnificent
unnamed formation, bounded on the E. by a broad lofty rampart flanking
Blanchinus, Lacaille, Delaunay, and Faye; and on the W. by Playfair and
the mountain arm just mentioned. It is fully 60 miles in length from N.
to S. Sunrise on this region affords a fine spectacle to the observer
with a large telescope. The best phase is when the morning terminator
intersects Aliacensis, as at this time the long jagged shadows of the E.
wall of Playfair and of the mountain arm are very prominent on the
smooth, greyish-blue surface of this immense enclosure.
PONTANUS.--An irregular ring-plain, 28 miles in diameter, S.S.W. of
Azophi, with a low broken border, interrupted on the S.W. by a smaller
ring-plain, which forms one of a group extending towards the S.W. The
dark floor includes a central mountain.
ALIACENSIS.--This ring-plain, 53 miles in diameter, with its neighbour
Werner on the N.E., are beautiful telescopic objects under a low sun. Its
lofty terraced border rises at one peak on the E. to the tremendous
height of 16,500 feet, and at another on the opposite side to nearly
12,000 feet above the floor. The wall on the S. is broken by a crater,
and on the W. traversed by narrow passes. There is also a prominent
crater on the inner slope of the N.E. wall. The floor includes a small
mountain, several little hills, and a crater.
WERNER.--A ring-plain, 45 miles in diameter, with a massive rampart
crowned by peaks almost as lofty as any on that of Aliacensis, and with
terraces fully as conspicuous. It has a magnificent central mountain,
4500 feet high. At the foot of the N.E. wall Madler observed a small
area, which he describes as rivalling the central peak of Aristarchus in
brilliancy. Webb, however, was unable to confirm this estimate, though he
noted it as very bright, and saw a minute black pit and narrow ravine
within it. Neison subsequently found that the black pit is a crater-cone.
It would perhaps be rash, with our limited knowledge of minute lunar
detail, to assert that Madler over-estimated the brightness of this area,
which may have been due to a _recent_ deposit round the orifice of the
crater-cone.
POISSON.--An irregular formation on the W. of Aliacensis, extending about
50 miles from W. to E., but much less in a meridional direction. Its N.
limits are marked by a number of overlapping ring-plains and craters, and
it is much broken elsewhere by smaller depressions. The E. wall is about
7000 feet in height.
GEMMA FRISIUS.--A great composite walled-plain, 80 miles or more in
length from N. to S., with a wall rising at one place nearly 14,000 feet
above the floor. It is broken on the N. by two fine ring-plains, each
about 20 miles in diameter, and on the E. by a third open to the E. There
is a central mountain, and several small craters on the floor, especially
on the W. side.
BUSCHING.--A ring-plain S. of Zagut, about 36 miles in diameter, with a
moderately high but irregular wall. There are several craterlets within
and some low hills.
BUCH.--Adjoins Busching on the S.E. It is about 31 miles in diameter, and
has a less broken barrier. There is a large crater on the E. wall, and
another smaller one on the S.W. Schmidt shows nothing on the floor, but
Neison noted two minute crater-cones.
MAUROLYCUS.--This unquestionably ranks as one of the grandest walled-
plains on the moon's visible surface, and when viewed under a low sun
presents a spectacle which is not easily effaced from the mind. Like so
many of the great enclosures in the fourth quadrant, it impresses one
with the notion that we have here the result of the crowding together of
a number of large rings which, when they were in a semi-fluid or viscous
condition, mutually deformed each other. It extends fully 150 miles from
E. to W., and more from N. to S.; so it may be taken to include an area
on the lunar globe which is, roughly speaking, equal to half the
superficies of Ireland. This vast space, bounded by one of the loftiest,
most massive, and prominently-terraced ramparts, includes ring-plains,
craters, crater-rows, and valleys,--in short, almost every type of lunar
formation. It towers on the E. to a height of nearly 14,000 feet above
the interior, and on the W., according to Schmidt, to a still greater
altitude. A fine rill-valley curves round the outer slope of the W. wall,
just below its crest, which is an easy object in a 8 1/2 inch reflector
when the opposite border is on the morning terminator, and could
doubtless be seen in a smaller instrument; and there is an especially
brilliant crater on the S. border, which is not visible till a somewhat
later stage of sunrise. The central mountain is of great altitude, its
loftiest peaks standing out amid the shadow long before a ray of sunlight
has reached the lower slopes of the walls. It is associated with a number
of smaller elevations. I have seen three considerable craters and several
smaller ones in the interior.
BAROCIUS.--A massive formation, about 50 miles in diameter, on the S.W.
side of Maurolycus, whose border it overlaps and considerably deforms.
Its wall rises on the E. to a height of 12,000 feet above the floor, and
is broken on the N.W. by two great ring-plains. On the inner slope of the
S.E. border is a curious oblong enclosure. There is nothing remarkable in
the interior. On the dusky grey plain W. of Maurolycus and Barocius there
is a number of little formations, many of them being of a very abnormal
shape, which are well worthy of examination. I have seen two short
unrecorded clefts in connection with these objects.
STOFLER.--A grand object, very similar in size and general character to
Maurolycus, its neighbour on the W. To view it and its surroundings at
the most striking phase, it should be observed when the morning
terminator lies a little E. of the W. wall. At this time the jagged,
clean-cut, shadows of the peaks on Faraday and the W. border, the fine
terraces, depressions, and other features on the illuminated section of
the gigantic rampart, and the smooth bluish-grey floor, combine to make a
most beautiful telescopic picture. At a peak on the N.E., the wall
attains a height of nearly 12,000 feet, but sinks to a little more than a
third of this height on the E. It is apparently loftiest on the N. The
most conspicuous of the many craters upon it is the bright deep circular
depression E. on the S. wall, and another, rather larger and less
regular, on the N.W., which has a very low rim on the side facing the
floor, and a craterlet on either side of the apparent gap. A large
lozenge-shaped enclosure abuts on the wall, near the crater E., with a
border crowned by a number of little peaks, which at an early stage of
sunrise resemble a chaplet of pearls. The floor of Stofler is apparently
very level, and in colour recalls the beautiful steel-grey tone of Plato
seen under certain conditions. I have noted several distinct little
craters on its surface, mostly on the N.E. side; and on the E. side a
triangular dark patch, close to the foot of the wall, very similar in
size and appearance to those within Alphonsus.
FARADAY.--A large ring-plain, about 35 miles in diameter, overlapping the
S.W. border of Stofler; its own rampart being overlapped in its turn by
two smaller ring-plains on the S.E., and by two still smaller formations
(one of which is square-shaped) on the N.W. The wall is broad and very
massive on the E. and N.E., prominently terraced, and includes many
brilliant little craters. Schmidt shows a ridge and several craters in
the interior.
LICETUS.--An irregular formation, about 50 miles in maximum width, on the
S. of Stofler, with the flanks of which it is connected by a coarse
valley. Neison points out that it consists of a group of ring-plains
united into one, owing to the separating walls having been partially
destroyed. This seems to be clearly the case, if Licetus is examined
under a low sun. On the E. side of the N. portion of the formation, the
wall rises to nearly 13,000 feet.
FERNELIUS.--A ring-plain, about 30 miles in diameter, abutting on the N.
wall of Stofler. It is overlapped on the E. by another similar formation
of about half its size. There are many craters and depressions on the
borders of both, and a large crater between the smaller enclosure and the
N.E. outer slope of Stofler. Schmidt shows eight craters on the floor of
Fernelius.
NONIUS.--A ring-plain, about 20 miles in diameter, abutting on the N.
wall of Fernelius. There is a prominent bright crater on the W. of it,
and another on the N., from which a delicate valley runs towards the W.
side of Walter.
CLAIRAUT.--A very peculiar formation, about 40 miles in diameter, S. of
Maurolycus, affording another good example of interference and
overlapping. The continuity of its border, nowhere very regular, has been
entirely destroyed on the S. by the subsequent formation of two large
rings, some 10 or 12 miles in diameter, the more easterly of which has,
in its turn, been partially wrecked on the N. by a smaller object of the
same class. There is also a ring-plain N.E. of Clairaut, which has very
clearly modified the shape of the border on this side. Two craters on the
floor of Clairaut are easy objects.
BACON.--A very fine ring-plain, 40 miles in diameter, S.W. of Clairaut.
At one peak on the E. the terraced wall rises to nearly 14,000 feet above
the interior. It is broken on the S. by three or four craters. On the W.
there is an irregular inconspicuous enclosure, whose contiguity has
apparently modified the shape of the border. There are two large rings on
the N. (the more easterly having a central peak), and a third on the E.
The floor appears to be devoid of prominent detail.
CUVIER.--A walled-plain, about 50 miles in diameter, on the S.E. of
Clairaut. The border on the E. rises to 12,000 feet; and on the N.W. is
much broken by depressions. Neison has seen a mound, with a minute crater
W. of it, on the otherwise undisturbed interior.
JACOBI.--A ring-plain S. of Cuvier, about 40 miles in diameter, with
walls much broken on the N. and S., but rising on the E. to nearly 10,000
feet. There is a group of craters (nearly central) on the floor. The
region S. of this formation abounds in large unnamed objects.
LILIUS.--An irregular ring-plain, 39 miles in diameter, with a rampart on
the E. nearly 10,000 feet above the floor. A smaller ring between it and
Jacobi has considerably inflected the wall towards the interior. It has a
conspicuous central mountain.
ZACH.--A massive formation, 46 miles in diameter, on the S. of Lilius,
with prominently terraced walls, rising on the E. to 13,000 feet above
the interior. A small ring-plain, whose wall stands 6000 feet above the
floor, is associated with the N. border. Two other rings, on the S.W. and
N.E. respectively, have craters on their ramparts and central hills.
PENTLAND.--A fine conspicuous formation under a low sun, even in a region
abounding in such objects. It is about 50 miles in diameter, with a
border exceeding in places 10,000 feet in height above the floor, which
includes an especially fine central mountain.
KINAU.--One of the group of remarkable ring-plains extending in a N.W.
direction from Pentland.
SIMPELIUS.--Another grand circumvallation, almost as large as Pentland,
but unfortunately much foreshortened. One of its peaks on the E. rises to
a height of more than 12,000 feet above the floor, on which there is a
small central mountain. Between Simpelius and Pentland are several ring-
plains, most of which appear to have been squeezed and deformed into
abnormal shapes.
CURTIUS.--A magnificent formation, about 50 miles in diameter, with one
of the loftiest ramparts on the visible surface, rising at a mountain
mass on the N.E. to more than 22,000 feet, an altitude which is only
surpassed by peaks on the walls of Newton and Casatus. There is a bright
crater on the S.E. border and another on the W. The formation is too near
the S. limb for satisfactory scrutiny. Between Curtius and Zach is a fine
group of unnamed enclosures.