In the accompanying brief notes on a few important formations, the diameter of each is given in miles, and the height of the highest peak on wall in feet. The day of each lunation on which it may be well seen is also added.
NO.
22. Maginus.—Great walled plain; 100 miles; 14,000 feet. Central mountain 2,000 feet. Difficult in full, owing to rays from Tycho. Plate XIV. Eighth and ninth days.
23. Longomontanus.—Walled plain; 90 miles; 13,314 feet. Crossed by rays from Tycho. Plate XV. Ninth day.
26. Wargentin; 28. Schickard.—Close together. 26. Curious ring plain; 54 miles. Seemingly filled with lava. 'Resembles a large thin cheese.' 28. Great walled plain; 134 miles; 9,000 feet. Floor 13,000 square miles area, very varied in colour. Walls would be invisible to spectator in centre of enclosure. Plate XII. Thirteenth and fourteenth days.
30. Tycho.—Splendid ring plain; 54 miles; 17,000 feet. Central mountain 5,000 feet. Great system of streaks from neighbourhood. Plates XII., XIII., XV. Ninth and tenth days.
32. StÖfler.—Walled plain. Peak on N.E. wall 12,000 feet. Floor very level. Beautiful steel-grey colour. Plate XVI. Seventh day.
33. Maurolycus.—Walled plain; 150 miles; 14,000 feet. In area equal to about half of Ireland. Floor in full covered with bright streaks. Plate XVI. Seventh day.
58. Piccolomini.—Ring plain; 57 miles; 15,000 feet on E. Fine central mountain. Very rugged neighbourhood. Plate XI. Fifth and sixth days.
63. Pitatus.—58 miles. Wall massive on S., but breached on N. side, facing Mare Nubium. Two clefts in interior shown Plate XV. Ninth day.
78. Fracastorius.—Another partially destroyed formation; 60 miles. Wall breached on N., facing Mare Nectaris. Under low sun traces of wall can be seen. Plate XI. Fifth and sixth days.
80. Petavius.—Fine object; 100 miles; 11,000 feet. Fine central peak 6,000 feet. Great cleft from central mountain to S.E. wall can be seen with 2-inch. Third and fourth days, but best seen on waning moon a day or two after full.
90. Gassendi.—Walled plain; 55 miles. Wall on N. broken by intrusive ring-plain of Gassendi A. Fine central mountain 4,000 feet. Between thirty and forty clefts in floor, more or less difficult. Plates XII., XIII. Eleventh and twelfth days.
95. Catherina; 96. Cyrillus; 97. Theophilus.—Fine group of three great walled plains. 95. Very irregular; 70 miles; 16,000 feet. Connected by rough valley with 96. 96 has outline approaching a square; walls much terraced, overlapped by 97, and partially ruined on N.E. side. 97 is one of the finest objects on moon; 64 miles; terraced wall, 18,000 feet. Fine central mountain 6,000 feet. Plates XI., XVI. Sixth day.
84. Arzachel; 110. Alphonsus; 111. PtolemÆus.—Another fine group. 84 is southernmost; 66 miles; 13,000 feet. Fine central mountain. 110. Walled plain; 83 miles; abutting on 111. Wall rises to 7,000 feet. Bright central peak. Three peculiar dark patches on floor, best seen towards full. 111 is largest of three; 115 miles. Many large saucer-shaped hollows on floor under low sun. Area 9,000 square miles. Plate XIII. Eighth and ninth days.
125. Grimaldi.—Darkest walled plain on moon; 148 miles by 129; area 14,000 square miles; 9,000 feet. Plate XII. Thirteenth and fourteenth days.
131. Messier and Messier A.—Two bright craters; 9 miles. Change suspected in relative sizes. From Messier A two straight light rays like comet's tail extend across Mare Foecunditatis. Fourth and fifth days.
147. Copernicus.—Grand object; 56 miles; 10,000 to 12,000 feet. Central mountain 2,400 feet. Centre of system of bright rays. On W. a remarkable crater row; good test for definition. Plates XII., XIII. Ninth and tenth days.
150. Triesnecker.—Small ring plain; 14 miles. Terraced wall 5,000 feet. Remarkable cleft-system on W. Rather delicate for small telescopes. Plate XIII. Seventh and eighth days.
158. Hyginus.—Crater-pit 3·7 miles. Remarkable cleft runs through it; visible with 2-inch: connected with AriadÆus rill to W., which also an object for a 2-inch. Dark spot to N.W. on Mare Vaporum named Hyginus N. Has been suspected to be new formation. Plate XII. Seventh day.
168. Eratosthenes.—Fine ring plain at end of Apennines; 38 miles. Terraced wall 16,000 feet above interior, which is 8,000 feet below Mare Imbrium. Fine central mountain. Plate XIII. Remarkable contrast to 148 Stadius, which has wall only 200 feet, with numbers of craters on floor. Ninth and tenth days.
175. Herodotus; 176. Aristarchus.—Interesting pair. 175 is 23 miles; 4,000 feet. Floor very dusky. Great serpentine valley; most interesting object. Easy with 2-inch. 176 is most brilliant crater on moon; 28 miles; 6,000 feet. Central peak very bright. Readily seen on dark part of moon by earth-shine. Plates XII., XIII. Twelfth day.
188. LinnÉ.—Small crater on M. Serenitatis near N.W. end of Apennines. Suspected of change, but varies much in appearance under different lights. Visible on Plate XVII. as whitish oval patch to left of end of Apennines. Seventh day.
191. Archimedes.—Fifty miles; 7,000 feet. Floor very flat; crossed by alternate bright and dark zones. Makes with 189 and 190 fine group well shown Plate XVII. Eighth day.
208. Eudoxus; 209. Aristoteles.—Beautiful pair of ring plains. 208 is 40 miles. Walls much terraced; 10,000 to 11,000 feet; 209 is 60 miles; 11,000 feet. Plate XVII. Sixth and seventh days.
210. Plato.—Great walled plain; 60 miles; 7,400 feet. Dark grey floor, which exhibits curious changes of colour under different lights, also spots and streaks too difficult for small telescope. Landslip on E. side. Shadows very fine at sunrise. Plates XII., XIII. Ninth day.
211. Pico.—Isolated mountain; 7,000 to 8,000 feet. S. of 210. Casts fine shadow when near terminator. Ninth and tenth days.
228. Atlas; 229. Hercules.—Beautiful pair. 228 is 55 miles; 11,000 feet. Small but distinct central mountain. 229 is 46 miles. Wall reaches same height as 228, and is finely terraced. Landslip on N. wall. Conspicuous crater on floor. Plate XI. Fifth day.
