London: Royal Society of London, 1840. Quarter Leather. First Edition. [xi]-[xii], [xi]-[xii], [iii]-viii, , -14, -620,  pp. 4to. Library binding, tan leather spine with gold embossed titling, scuffing and tears where call numbers have been removed. Interiors clean, ex-library stamp on title page, and occurring sporadically within. Numerous folding plates that illustrate articles. Pages were trimmed slightly when rebound. Very Good.
William Parson's (1800-1867) article outlining his design and construction of the reflecting telescope that provided him with the technology to make his observations and first identification of the spiral nebulae disseminated by him in our #27507, "Observations on the Nebulae" (Philosophical Transactions of the Royal Society of London, Vol. 140 for the Year 1850 Part II, pp. 499-514).