Observations of the Appearances among the Fix'd Stars, Called Nebulous Stars. By W. Derham, D. D. Canon of Windsor, F. R. S.

VI. He who knows perfectly the Method of making Phosphorus, can choose whether he will sublime his Magma of Urine into Phosphorus, or into Sulphur; for the Difference consists only in the Encheiresis. III. Observations of the Appearances among the Fix'd Stars, called Nebulous Stars. By W. Derham, D.D. Canon of Windsor, F.R.S. HAVING last Autumn made some good Observations, with my eight Foot Reflecting Telescope, of the Appearances in the Heavens, called Nebulous Stars, I think it proper to acquaint this Illustrious Society with them, to instigate others to make farther Observations of them, because I think there is much more in them worthy of the Inquiry of the Curious, than hath hitherto been imagined, and because I fear I shall not be able to pursue my Observations much farther, by reason my Reflector loseth its Excellence and Power, by beginning to be tarnished. But if any one would have a good View of these Nebulofæ, it is of absolute Necessity that he makes use of very good Glasses, else all his Labour will be lost, as I found by Experience. These Appearances in the Heavens, have born the Name of Nebulous Stars: But neither are they Stars, nor such Bodies as emit, or reflect Light, as the Sun, Moon, and Stars do; nor are they Conge- ries, or Clusters of Stars, as the Milky-Way: but whitish Area, like a Collection of Misty Vapours: whence they have their Name. There are many of them dispersed about, in di- verse Parts of the Heavens. This Catalogue of them (which I transcribed from Hevelius's Prodromus Astronomiae) may be of good use to such as are minded to enquire into them. A Catalogue of the Nebulosa, extracted from Hevelius. | The Places of the Nebulosa | Their R. Afc. cent. A.D. 1660 | Their Declinat. A.D. 1660 | |---------------------------|-------------------------------|--------------------------| | | gr. ' " | gr. ' " | | In Andromeda's Girdle, | 6 4 45 | 39 27 57 N. | | In Forehead of Capricorn, | 300 2 53 | 20 1 53 S. | | Another preceding the | 301 59 55 | 19 11 30 S. | | Eye of Capricorn, | 302 35 9 | 19 36 0 S. | | Another following it, | 302 25 31 | 18 48 58 S. | | One above those, adjoin- | 304 54 8 | 47 54 20 N. | | ing to the Eye of Capri- | 312 10 5 | 53 05 20 N. | | corn, | | | | Preceding above the Swan's Tail, and last in its N. Foot, | 264 52 46 48 9 10 N. | | One following a Star above the Swan's Tail, out of the Constellation, | 265 38 37 38 5 50 N. | | On the outside of Hercules's left Foot, | K | | In the left Leg of Hercules, | On | | The Places of the Nebulose | Their R. Asc. cent. A.D. 1660 | Their Declinat. A.D. 1660 | |---------------------------|-------------------------------|--------------------------| | | gr. | " | gr. | " | | On the Top of Hercules's Head, | 252 | 24 | 3 | 13 | 18 | 37 N. | | At the Ear of Pegasus, | 332 | 38 | 45 | 3 | 3 | 12 N. | | In the Western Border of Sobieski's Shield, | 272 | 32 | 34 | 14 | 23 | 35 S. | | Under the Beam of the Scales of Libra, | 219 | 26 | 15 | 9 | 16 | 27 S. | | Above the Back of Ursa major, | 183 | 32 | 41 | 60 | 20 | 33 N. | | In the third Joint of Scorpio's Tail, | 12 | 43 | 00 | 19 | 1 | 0 | | Between Scorpio's Tail, and the Bow of Sagittarius, | 24 | 32 | 00 | 11 | 25 | 0 | Besides these Dr. Halley, in Phil. Trans. No 347, hath mentioned one in Orion's Sword; another in Sagittary; a third in the Centaur (never seen in England) a fourth preceding the right Foot of Antinous; a fifth in Hercules; and that in Andromeda's Girdle. Five of these six I have carefully viewed with my excellent eight Foot Reflecting Telescope, and find them to be Phænomena much alike; all except that preceding the right Foot of Antinous, which is not a Nebulose, but a Cluster of Stars, somewhat like that which is in the Milky-Way. Between the other four, I find no material Difference, only some are rounder, some of a more oval Form, without any Fix'd Stars in them to cause their Light; only that in Orion, hath some Stars in it, visible only with the Telescope, but by no Means sufficient to cause the Light of the Nebulose there. But by these Stars it was, that I first perceived the Distance of the Nebulose to be greater than that of the Fix'd Stars, and put me upon enquiring into the rest of them. Every one of which I could very visibly, and plainly discern, to be at immense Distances beyond the Fix'd Stars near them, whether visible to the naked Eye, or Telescopick only; yea, they seemed to be as far beyond the Fix'd Stars, as any of those Stars are from the Earth. And now from this Relation of what I have observed from very good, and frequent Views of the Nebulose, I conclude them certainly not to be Lucid Bodies, that send their Light to us, as the Sun and Moon. Neither are they the combined Light of Clusters of Stars, like that of the Milky-Way: But I take them to be vast Areæ, or Regions of Light, infallibly beyond the Fix'd Stars, and devoid of them. I say Regions, meaning Spaces of a vast Extent, large enough to appear of such a Size as they do to us, at so great a Distance as they are from us. And since those Spaces are devoid of Stars, and even that in Orion itself, hath its Stars bearing a very small Proportion to its Nebulose, and they are visibly not the Cause of it, I leave it to the great Sagacity and Penetration of this Illustrious Society, to judge whe- ther these Nebulose are particular Spaces of Light; or rather, whether they may not, in all Probability, be Chasms, or Openings into an immense Region of Light, beyond the Fix'd Stars. Because I find in this Opinion most of the Learned in all Ages (both Philosophers, and I may add Divines too) thus far concurred, that there was a Region beyond the Stars. Those that imagined there were Crystalline, or Solid Orbs, thought a Coelum Empyraeum was beyond them and the Primum Mobile: and they, that maintained there were no such Orbs, but that the Heavenly Bodies floated in the Aether, imagined that the Starry Region was not the Bounds of the Universe, but that there was a Region beyond that, which they called the Third Region, and Third Heaven. To conclude these Remarks, it may be of use to take Notice, that in Hevelius's Nebulose, some seem to be more large, and remarkable than others; but whether they are really so, or no, I confess I have not had an Opportunity to see, except that in Andromeda's Girdle, which is as considerable as any I have seen. In his Maps of the Constellations, the most remarkable are the three near the Eye of Capricorn; that in Hercules's Foot; that in the third Joint of Scorpio's Tail; and that between Scorpio's Tail and the Bow of Sagittary. But if any one is desirous to have a good View of these, or any other of the Nebulose, it is absolutely necessary that he should make use of very good Glasses, else all his Labour will be in vain, as I have found by Experience, and before noted.