OF THE SURFACE OF THE MOON. 
345 
to the north of Aristarchus has been five times drawn by me, often with difficulty, for 
the appearances are very variable, with small differences of light. My results agree in 
general with that of the Athenian astronomer, and with an earlier map published by 
Mad lee in 1837. I hope to complete a drawing of this tract. 
In Plate XVII. Herodotus and the famous rill from it are merely sketched freely, to 
show the general course of the rill, and its opening into a seeming delta. The eastern 
border of the seeming delta (E) is treated as a rill by Schmidt and Madlee, and so it has 
always appeared to me in the part marked r, which turns up to the south so as to be 
rudely parallel to the first or main part of the rill from Herodotus, and seems to begin 
under a crest of mountain. The smaller notch in this outline (at E) has only been 
noted once. The western branch (IP) is not marked as a rill by Schmidt, but may be 
traced on his map as a kind of coast by the line of the promontories, and so traced agrees 
with my outline. I propose to complete the drawing of this part of the moon in the 
next summer. 
Plate 2 of Schmidt’s memoir contains map-sketches of rills lying east of Campanus, 
which I have also drawn. The appearances in this region differ somewhat from the 
map of Madlee, and the rills in particular are very interesting from their number, 
general parallelism, partial concurrence, and distinct relation to small and large craters. 
In a third plate of the same memoir is a diagram map of Gassendi, and the region to 
the south, which may be compared with my drawing,. Plate XV. fig. 1. The agree- 
ment is quite satisfactory in the general sweep and breaks of the border, the digitated 
central mass, the small craters in the area, the complexity of the eastern crest and 
slopes. 
There is some difference requiring reexamination in regard to the sculpture of the 
interior, and the linear inequalities, some of which are marked as distinct rills by 
Schmidt. I shall take an early opportunity of making a careful study of the points of 
difference. 
