On the Proper Motion of the Solar System (Galloway, pp. 79-109; Read on April 15, 1847; Published 1848) WITH On the Cause of the Discrepancies Observed by Mr. Baily with the Cavendish Apparatus for Determining the Mean Density of the Earth (Hearn & Whitehead, pp. 217-229 in Philosophical Transactions of the Royal Society of London 137, 1848

FIRST EDITION, FULL VOLUME, OF THE EARLIEST DEFINITIVE ANALYSIS OF THE PROPER MOTION OF THE SOLAR SYSTEM; Thomas Galloway was a Scottish mathematician; this paper was the most important of his career and won him the prestigious Royal Medal. The 'Proper motion of the Solar System' is a phrase used to describe the absolute motion of the Solar System through deep space toward or away from the 'fixed stars.' Galloway's paper presented the results of his calculations for determining the direction of the proper motion of the solar system from the apparent proper motions of stars in the southern hemisphere. (The 'proper motion of the stars' refers to the change in position of the stars relative to the Earth over the course of many years, as measured in seconds of arc per year.) Galloway "used Gauss' method of least squares and principle of least constraint to attribute individual motion components to each star and our Solar System to develop his equations for the motion of 300 southern hemisphere stars" (The Wenner Collection). Galloway drew his data from a comparison of the observations made in the 1750s by Lacaille at the Cape with the observations of Johnson and Professor Henderson at St. Helena and the Cape in the 1830s. ALSO INCLUDED: Baily and Whitehead attribute discrepancies in calculations of the Earth's mean density to the influence of magnetism. ALSO INCLUDED: William R. Grove's Bakerian Lecture, "On certain Phenomena of Voltaic Ignition and the Decomposition of Water into its constituent Gases by Heat" (pp. 1-17). "While investigating the electrolysis of water, Grove observed that when the current was switched off, a small current flowed through the circuit in the opposite direction, as a result of a reaction between the electrolysis products, hydrogen and oxygen, catalyzed by the platinum electrodes. Grove recognized the possibility of combining several of these in series to form a gaseous voltaic battery, also [making] the crucially important observation that there must be a 'notable surface of action' between the gas, the electrolyte, and the electrode phases in a cell" (Stolten, Hydrogen and Fuel Cells, 63). Note that we offer Grove's seminal 1838 fuel cell paper separately. ALSO INCLUDED: Antoine François Jean Claudet's paper "On different properties of Solar Radiation" (pp. 253-263). Here Claudet discusses "the properties of solar radiation modified by colored glass media, he made a bold attempt to lay the foundation of a more complete theory of the photographic phenomena" (Wikisource). ALSO INCLUDED: Carlo Matteucci's "Electro-Physiological Researches", the fifth, sixth, and seventh series (pp. 231-249). CONDITION & DETAILS: 4to. 11.25 x 9 inches. Full volume, complete. Single small ex-libris stamp on the rear of half-title; no other markings. 13 plates. Handsomely rebound in gilt-ruled calf over marbled paper boards. 5 raised bands at the spine, each gilt-ruled; gilt-tooled fleur de lis at the spine. Red and black, gilt-lettered spine labels. Tightly and solidly bound. New endpapers. Bright and clean throughout. Near fine condition.…