[8] As represented by Nasmyth's models in plaster.
[9] Ball, loc. cit., p. 67.
[10] Ball, loc. cit., p. 69.
[11] Astronomy, p. 78.
[12] Outlines of Astronomy, p. 285.
[13] At rare intervals a few crescent-shaped ridges are discernible on the lunar sphere, but it is very doubtful if they are to be regarded as breached craters.
[14] The number of "spots" on the moon was considered to be 244 until Schroter increased it to 6,000, and accurately described many of them. Schroter seems to have been the earliest observer who identified the circular hollows on the moon's surface as volcanic craters.
[15] Drawings of these very curious forms are given by Judd, Volcanoes, p. 127.