Photographed with the Lick Telescope.] It is not my intention to give a complete description of the various lunar features, and I mention but one other--the "clefts" or "rills," which are to be seen running across the surface like cracks.

One of the most remarkable of these is found in the _Oceanus Procellarum_, near the crater-mountain Aristarchus, which is famed for the intense brilliance of its central peak, whose reflective power is so great that it was once supposed to be aflame with volcanic fire.

The cleft, or crack, in question is very erratic in its course, and many miles in length, and it terminates in a ringed plain named Herodotus not far east of Aristarchus, breaking through the wall of the plain and entering the interior.

Many other similar chasms or canons exist on the moon, some crossing plains, some cleaving mountain walls, and some forming a network of intersecting clefts.

Mr.Thomas Gwyn Elger has this to say on the subject of the lunar clefts: "If, as seems most probable, these gigantic cracks are due to contractions of the moon's surface, it is not impossible, in spite of the assertions of the text-books to the effect that our satellite is now a 'changeless world,' that emanations may proceed from these fissures, even if, under the monthly alternations of extreme temperatures, surface changes do not now occasionally take place from this cause also.