[Footnote 1: Such a telescope is most powerful with the shortest sight. It may be remarked that the use of a telescope often reveals a difference in the sight of the two eyes. In my own case, for instance, I have found that the left eye is very short-sighted, the sight of the right eye being of about the average range. Accordingly with my left eye a 5-1/2-foot object-glass, alone, forms an effective telescope, with which I can see Jupiter's moons quite distinctly, and under favourable circumstances even Saturn's rings. I find that the full moon is too bright to be observed in this way without pain, except at low altitudes.]
[Footnote 2: Betelgeuse--commonly interpreted the Giant's Shoulder--_ibt-al-jauza_. The words, however, really signify, "the armpit of the central one," Orion being so named because he is divided centrally by the equator.]
[Footnote 3: I have never been able to see more than four with a 3-3/4-inch aperture. I give a view of the trapezium as seen with an 8-inch equatorial.]
[Footnote 4: Sir W. Herschel several times saw [epsilon] Lyræ as a double. Bessel also relates that when he was a lad of thirteen he could see this star double. I think persons having average eye-sight could see it double if they selected a suitable hour for observation. My own eye-sight is not good enough for this, but I can distinctly see this star wedged whenever the line joining the components is inclined about 45° to the horizon, and also when Lyra is near the zenith.]
[Footnote 5: They were so described by Admiral Smyth in 1839. Mr. Main, in 1862, describes them as straw-coloured and reddish, while Mr. Webb, in 1865, saw them pale-yellow and _lilac_!]
[Footnote 6: Or the observer may sweep from [omicron] towards [nu], looking for R about two-fifths of the way from [omicron] to [nu].]
[Footnote 7: Here a single period only is taken, to get back to a convenient hour of the evening.]
[Footnote 8: Here a single period only is taken, to get back to a convenient hour of the evening.]
[Footnote 9: I have constructed a zodiac-chart, which will enable the student to mark in the path of a planet, at any season of the year, from the recorded places in the almanacs.]
[Footnote 10: It is convenient to remember that through precession a star near the ecliptic shifts as respects the R.A. and Dec. lines, through an arc of one degree--or nearly twice the moon's diameter--in about 72 years, all other stars through a less arc.]