“Spots on the Sun” were remarked long before the telescope came into service. In the early Chinese annals many references are made to these objects; thus, in A.D. 188, February 14, it is recorded—“The colour of the Sun reddish-yellow; a fleckle in the Sun (bird-shaped).” Other ancient notices compare the spots to a flying bird, an apple, or an egg. Many spots were seen in later years, especially in 321, 807, 840, 1096, &c. In 807 a large black spot upon the Sun was watched during a period of eight days. It reflects much credit upon observers of a past age that they performed so many useful feats of observation, though relying simply upon the powers with which Nature alone had endowed them. They anticipated the telescope in some important discoveries. Large sun-spots are not, it is true, difficult features to perceive with the naked eye under certain circumstances; for whenever there is a fog or haze sufficiently dense to veil the lustre of the Sun in suitable degree, they can be readily seen, presuming, of course, that such spots are in existence at the time. They are sometimes observed, in a purely casual way, by people who may happen to glance at the Sun when he is involved in fog and looks like a dull, red ball suspended in the firmament. On one occasion, near sunset, in the autumn of 1870, I saw four large spots on different parts of the Sun, and these phenomena were very numerous at about this time. When spots attain a diameter of 50″ or more they may be detected by persons of good sight; but if the Sun is high and clear, coloured glass must be used to defend the eye.
Doubt hangs over the question as to the first telescopic observer of the spots. It is certain that Fabricius, Galilei, Harriot, and Scheiner all remarked them in about the year 1611; and of these Fabricius perhaps deserves the chief praise, as the first who published a memoir on the subject. Galilei appears undoubtedly to have had priority in recognizing the bright spots, or _faculæ_. Scheiner discovered that the black spots, or _maculæ_, are composed of a dark umbra and a fainter outlying shade, called the penumbra. Arago quotes him as having also described the Sun as “covered over its whole surface with very small, bright, and obscure points, or with lively and sombre streaks of very slender dimensions, crossing each other in all directions.” He announced, too, that the spots were confined to a narrow zone on the north and south sides of the equator, and this he termed the “Royal Zone.”