Some grave difficulties appear to have marked the attempts of the earlier observers; for they did not all use coloured glasses, and the dazzling light of the Sun, intensified by their lenses, often overpowered the sight, and so we find them awaiting opportunities when fog partly obscured the Sun near his rising or setting. Thus Harriot, who seems to have noticed and figured three sun-spots as early as 1610, Dec. 8, says:—“The altitude of the Sonne being 7 or 8 degrees, and it being a frost and a mist, I saw the Sonne in this manner.” His drawing followed. On another occasion he says:—“A notable mist: I observed the Sonne at sundry times, when it was fit.” Fabricius advised other observers to commence their observations by admitting only a small portion of the Sun into the field, so that the eye might be prepared to receive the light of the entire disk. Galilei was equally unaware of the advantage of tinted glass, and adopted the expedient of scanning the Sun when placed in the vicinity of the horizon. He remarks that “the spot of 1612, April 5 appeared at sunset;” and his writings contain other references of similar import. Scheiner, however, appears to have been more alive to the requirements of the work, and employed a plain green glass placed in front of the object-lens of his telescope. Under the various circumstances we have been alluding to, the views obtained of the solar surface must necessarily have been of a very defective character, and the old observers at least deserve our sympathy in their exertions. No such obstacles confront the observer now. He has everything provided for him. Instrumental devices rob the Sun of his noonday brilliancy, and the eye serenely scans the details of his expansive image without the slightest pain or effort.