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Updated: May 23, 2025
On a line from beta to gamma, and about one third of the distance from the former to the latter, is the celebrated Ring Nebula, indicated on the map by the number 4447. We need all the light we can get to see this object well, and so, although the three-inch will show it, we shall use the five-inch.
Its doubles may be summarized as follows: 11, magnitudes five and nine, distance 17.4", p. 252°; pi, magnitudes six and seven, distance 1.6", p. 122°; 23, magnitudes six and ten, distance 3.4", p. 12° requires the five-inch and good seeing; 57, magnitudes five and six, distance 36", p. 170°; Sigma 2654, magnitudes six and eight, distance 12", p. 234°; Sigma 2644, magnitudes six and seven, distance 3.6", p. 208°.
When reddest, it has been described as "scarlet," "crimson," and "blood-colored"; when palest, it is a deep orange-red. Its light variation has a period the precise length of which is not yet known. The cycle of change is included between the eighth and ninth magnitudes. While our three-inch telescope suffices to show R, it is better to use the five-inch, because of the faintness of the star.
This difference is, of course, atmospheric in origin, although it may be partly subjective, depending upon the mental influences of the mutations of Nature. We shall begin our night's work with this object, and the four-inch glass will serve our purpose, although the untrained observer would be more certain of success with the five-inch.
The admiral was pleased and proud, and happy.... It was an excellent order, but it wasn't true. The admiral wasn't happy. Not after battle photographs were developed and he could see how the alien ship had dodged rockets with perfect ease, and had actually taken a five-inch shell, which exploded on impact, without a particle of damage.
I am acquainted with an astronomer of long experience in the use of telescopes, whose eye is so deficient in color sense that he denies that there are any decided colors among the stars. Such persons miss one of the finest pleasures of the telescope. In examining theta Virginis we shall do best to use our largest aperture, viz., the five-inch.
It would be useless to look for the two fainter companions of delta, discovered by Burnham, even with our five-inch glass. But we shall probably need the five-inch for our next attempt, and it will be well to put on a high power, say three hundred diameters. The star to be examined is the little brilliant dangling below the right-hand end of the Belt, toward Rigel. It appears on the map as eta.
Heaven knows I find it hard enough to be honest, with no tempter but the Devil and my own thoughts; and, if I have you also to contend with, there is little hope of me." "Nay, that is true. Your good resolutions were always like cobwebs, and your evil habits like five-inch cables," replied the traveller. "I am to understand, then, that you refuse my offer?"
The next in importance was a nine and a half-inch instrument at Dorpat, in Russia. This was the telescope through which the astronomer Struve made his earlier studies and discoveries. His field of observation was for the most part the fixed and double stars. At this time the largest instrument in the United States was the five-inch refractor of Yale College.
Jupiter is perhaps the easiest of all the planets for the amateur observer. A three-inch telescope gives beautiful views of the great planet, although a four-inch or a five-inch is of course better. But there is no necessity for going beyond six inches' aperture in any case. For myself, I should care for nothing better than my Byrne five-inch of fifty-two inches' focal distance.
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