Page:Micrographia - or some physiological descriptions of minute bodies made by magnifying glasses with observations and inquiries thereupon.djvu/357

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Aving, in the last Observation, premis'd some particulars observable in the medium, through which we must look upon Cœlestial Objects, I shall here add one Observation of the Bodies themselves; and for a specimen I have made choice of the Pleiades, or seven Stars, commonly so called (though in our time and Climate there appear no more then six to the naked eye) and this I did the rather, because the deservedly famous Galileo, having publisht a Picture of this Asterisme, was able, it seems, with his Glass to discover no more then thirty six, whereas with a pretty good twelve foot Telescope, by which I drew this 38 Iconism, I could very plainly discover seventy eight, placed in the order they are ranged in the Figure, and of as many differing Magnitudes as the Asterisks, wherewith they are Marked, do specifie; there being no less then fourteen several Magnitudes of those Stars, which are compris'd within the draught, the biggest whereof is not accounted greater then one of the third Magnitude; and indeed that account is much too big, if it be compared with other Stars of the third Magnitude, especially by the help of a Telescope; for then by it may be perceiv'd, that its splendor, to the naked eye, may be somewhat augmented by the three little Stars immediately above it, which are near adjoyning to it. The Telescope also discovers a great variety, even in the bigness of those, commonly reckon'd, of the first, second, third, fourth, fifth, and sixth Magnitude; so that should they be distinguish'd thereby, those six Magnitudes would, at least, afford no less then thrice that number of Magnitudes, plainly enough distinguishable by their Magnitude, and brightness; so that a good twelve foot Glass would afford us no less then twenty five several Magnitudes. Nor are these all, but a longer Glass does yet further, both more nicely distinguish the Magnitudes of those already noted, and also discover several other of smaller Magnitudes, not discernable by the twelve foot Glass: Thus have I been able, with a good thirty six foot Glass, to discover many more Stars in the Pleiades then are here delineated, and those of three or four distinct Magnitudes less then any of those spots of the fourteenth Magnitude. And by the twinkling of divers other places of this Asterisme, when the Sky was very clear, I am apt to think, that with longer Glasses, or such as would bear a bigger aperture, there might be discovered multitudes of other small Stars, yet inconspicuous. And indeed, for the discovery of small Stars, the bigger the aperture be, the better adapted is the Glass; for though perhaps it does make the several specks more radiant, and glaring, yet by that means, uniting more Rays very near to one point, it does make many of those radiant points Rh