Lacus Solis

The one marking was named by Schiaparelli the Lacus Solis, the other, the Sinus Sabæus, and they are two of the best known and most easily recognized of the planet’s features; so that it is easy to trace the growth of our knowledge of both of them from 1830 up to the present time.

Now the gradation in size, from the Lacus Solis down to the smallest oasis of Lowell, is a complete one.

Prof. Lowell’s two hundred oases, with few exceptions, seem all of the same character; is it possible to suppose, if telescopes develop in the future as they have done in the past, that the two hundred oases will preserve their uniformity of appearance any more than the Lacus Solis and the head of the Sinus Sabæus?

If a novice begins to work upon Mars with a small telescope, he will draw the Lacus Solis and the Sinus Sabæus as two round, uniform spots, and as he gains experience, and his instrumental power is increased, he will begin to detect detail in them, and draw them as Dawes and Schiaparelli and others have shown them later.

Occasionally, as occurs at the singular spot named Lacus Solis, several canals converging from all points of the compass meet at a central point like the spokes of a wheel; in other cases, as, for instance, that of the long canal named Eumenides, with its continuation Orcus, a single conspicuous line is seen threading a large number of round dark spots, which present the appearance of a row of beads upon a string.