The sidereal messenger of Galileo Galilei : and a part of the preface to Kepler's Dioptrics containing the original account of Galileo's astronomical discoveries . in the figure given, forseveral bright excrescences, as they may be called,extend beyond the boundary of light and shadowinto the dark part, and on the other hand piecesof shadow encroach upon the light:—nay, even agreat quantity of small blackish spots, altogetherseparated from the dark part, sprinkle everywherealmost the whole space which is at the time floodedwith the Suns light, with the exception of that partalone which is occu
The sidereal messenger of Galileo Galilei : and a part of the preface to Kepler's Dioptrics containing the original account of Galileo's astronomical discoveries . in the figure given, forseveral bright excrescences, as they may be called,extend beyond the boundary of light and shadowinto the dark part, and on the other hand piecesof shadow encroach upon the light:—nay, even agreat quantity of small blackish spots, altogetherseparated from the dark part, sprinkle everywherealmost the whole space which is at the time floodedwith the Suns light, with the exception of that partalone which is occupied by the great and ancient have noticed that the small spots just mentionedhave this common characteristic always and in everycase, that they have the dark part towards the Sunsposition, and on the side away from the Sun theyhave brighter boundaries, as if they were crownedwith shining summits. Now we have an appearancequite similar on the Earth about sunrise, when webehold the valleys, not yet flooded with light, but themountains surrounding them on the side opposite tothe Sun already ablaze mth the splendour of his Sketches by Galileo to shew. the shape of a lunar mountain and of a walled plain. Galileo: Sidereua Nundus, Venice 1610. THE SIDEREAL MESSENGER. 17 beams; and just as the shadows in the hollows of theEarth diminish in size as the Sun rises higher, soalso these spots on the Moon lose their blackness as theilluminated part grows larger and larger. Again, notonly are the boundaries of light and shadow in theMoon seen to be uneven and sinuous, but—and thisproduces still greater astonishment—there appear verymany bright points within the darkened portion of theMoon, altogether divided and broken off from theilluminated tract, and separated from it by no incon-siderable interval, which, after a little while, graduallyincrease in size and brightness, and after an hour ortwo become joined on to the rest of the bright portion,now become somewhat larger; but
Size: 1133px × 2206px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorgalileigalileo1, bookcentury1800, booksubjectastronomy
