On the ring of Saturn, and the rotation of the fifth satellite upon its axis. Article read December 15, 1791.

London, The Royal Society, 1792. Large 4to (28.8 x 22.9 cm). viii, 196, 26 pp.; three folding engraved plates (including 22 pp. and one folding engraved plate to Herschel's paper). Original blind grey wrappers. = Early, rare publication about Herschel's discoveries related to the rings being divided, drawn from the discovery of quick rotation. Also included is a ten pages study, partly based on observations by Cassini, on the rotation period of the fifth moon of Saturn, Rhea. This is the Society's Philosophical Transactions volume 82 part I. This volume also contains: Miscellaneous Observations (five pp.) by Herschel, which includes an account of a comet (December 22, 1791), and remarks on variable stars, viz. on one disappearing in Hercules, and on the red giant, Alpha Ceti. Other papers in this volume are by Thomas Wedgwood (Experiments and observations on the production of light from different bodies, by heat and attrition), Benjamin Thompson (Experiments upon heat), and others. Uncut. Rear wrapper detached, wrappers, and first few leaves lightly damp stained, the Herschel papers only so in the lower, untrimmed bottom margin. In all a good copy. Houzeau & Lacaster, p. 1430.