The largest spot which ever came under my observation was seen during the period from the 13th to the 19th of November, 1870. This spot, which was on the northern hemisphere of the Sun, was conspicuous among the smaller spots constituting the group to which it belonged, and followed them on the east. On November 16th, when it attained its largest size, the diameter of its penumbra occupied fully one-fifth of the diameter of the Sun; its real diameter being, therefore, not less than 172,000 miles, or nearly 22 times the diameter of the Earth. As the umbra of this spot occupied a little more than one-third of its whole diameter, seven globes like our own, placed side by side on a straight line, could easily have passed through this immense gap. To fill the area of this opening, about 45 such globes would have been needed. This spot was, of course, very easily seen with the naked eye, its diameter being almost eight times that required for a spot to be visible without a telescope. Ancient historians often speak of obscurations of the Sun, and it has been supposed by some astronomers that this phenomenon might have been due in some cases to the apparition of large spots. A few spots on the surface of the Sun, like that just described, would sensibly reduce its light. Besides the ordinary Sun-spots already described, others are at times observed on the surface of the Sun, which show some of the same characteristics, but never attain so large proportions. They always appear as if seen through a fog, or veil, between the granulations of the solar surface. On account of their vagueness and ill-defined contours, I have proposed for these objects the term, "_Veiled Spots_." Veiled spots have a shorter duration than the ordinary spots, the smaller types sometimes forming and vanishing in a few minutes. Some of the larger veiled spots, however, remain visible for several days in succession, and show the characteristics of other spots in regard to the arrangement of their parts.