1 Some of our readers may not know that light travels, in round numbers, at the rate of 186,000 miles a second.

2 The terminator represents the limit of light on that side of the planet in the shade, in other words, where the light terminates. In viewing the Moon, when at quarter or half, the terminator is seen very ragged on account of the illumination of higher points on the surface. If the Moon was as smooth as a billiard ball the terminator would be clear cut.

3 The world in its ignorance of Italian assumed that the word meant exclusively canals, and, if canals, then dug by shovels. What! a canal thirty miles wide and two thousand miles long dug in the snap of the finger? Impossible conception, you say. We shall see later the sober utterances of a member of the British Astronomical Society on this gratuitous assumption, and an equally serious comment by the chief assistant of the Royal Observatory at Greenwich (E.S. M.).

4 The views so long held that the dark shaded regions were bodies of water, or seas, was disproved by the observations of Pickering and Douglass, who distinctly traced the course of the canals across these dark areas. The observations of Dr. E. Barnard certainly sustain the contention that they are land areas and probably depressions, representing ancient ocean beds. Dr. Barnard, using the telescope at the Lick Observatory, says: "Under the best conditions these dark regions which are always shown, with smaller telescopes, of nearly uniform shade, broke up into a vast amount of very fine details. I hardly know how to describe the appearance of these 'Seas' under these conditions. To those, however, who have looked down upon a mountainous country from a considerable elevation, perhaps some conception of the appearance presented by these dark regions may be had. From what I know of the appearance of the country about Mt. Hamilton, as seen from the Observatory, I can imagine that, as viewed from a very great elevation, this region, broken by caÑon, and slope and ridge, would look like the surface of these Martian seas."

5 Sterling Heiley, in "Pearson's Magazine," June, 1905.

6 A translation of which may be found in the "Popular Science Monthly," Vol. XXXV, p. 532.

7 I may add that in a similar case an American student of Mars moved his telescope to Mexico and remounted it at a cost of some thousands of dollars.