Description: Quadrant electrometer.

Caption: This accurate instrument worked on a suspended vane that is free to rotate on its supporting wire in a uniform electric field formed by the four segments, the quadrants, of a hollow disk. When in use, the glass leyden jar surrounding the quadrants was charged with electricity. the vane picked up this charge from a platinum 'trailing' wire that dipped into a pool of concentrated sulphuric acid. The acid acted as both a conductor and drying agent.

Introduction: Kelvin's greatest achievement in the field of static electricity was the development of a series of electrometers, of which this is one. they were used in the laboratory as standards for calibrating other instruments. They were also used for measuring potentials of both static and direct current electricity.

Background: This instrument was made shortly after Lord Kelvin first demonstrated the quadrant electrometer at a meeting of the British Association for the Advancement of Science, in 1867, at Dundee.

Reference: Green, George & Lloyd, John T.. "Kelvin's Instruments and the Kelvin Museum", 1970 p. 59

Reference: Holbrook, Mary. "Science Preserved A Directory of Scientific Instruments in the collections in the United Kingdom and Eire p. 132", 1992

Reference: Dee, Philip I.. "Fortuna Domus: a series of lectures delivered in the University of Glasgow in commemoration of the fifth centenary of its foundation p. 332", 1952

Historical Context: Design of the Coulomb balance - When: 1784 - Where: France - Who: Coulomb, Charles Augustin de (1736-1806) French physicist

Historical Context: Design of the quadrant electrometer - When: 1867 - Where: Glasgow, Scotland - Who: Thomson, William, Professor (1824-1907) Sir William Thomson from 1866 and Ist Baron Kelvin of Largs from 1892 better known as Lord Kelvin

Historical Context: Manufacture - When: circa 1867 - Where: 95 Buchanan Street or 78 Union Street, Glasgow, Scotland - Who: James White & Company

Historical Context: Publication of the invention of Gilbert's "versorium" in "De Magnete" - When: 1600 - Where: London, England

Historical Context: Publication of the invention of the electroscope Gilbert called a "versorium" in "De Magnete" - Who: William Gilbert (1540-1603) English physician

Historical Context: Used at the Gilbert Scott Buildings in lecture demonstrations in the Department of Natural Philosophy - Who: Thomson, William, Professor (1824-1907) Sir William Thomson from 1866 and Ist Baron Kelvin of Largs from 1892 better known as Lord Kelvin

Historical Context: Used at the Old College in lecture demonstrations in the Department of Natural Philosophy - Who: Thomson, William, Professor (1824-1907) Sir William Thomson from 1866 and Ist Baron Kelvin of Largs from 1892 better known as Lord Kelvin

Historical Context: Used in the Department of Natural Philosophy now called the Department of Physics and Astronomy - Where: Natural Philosophy Department, Gilbert Scott Building, University of Glasgow, University Avenue, Glasgow, Scotland - Where: Natural Philosophy Lecture Theatre, Old College, University of Glasgow, High Street, Glasgow, Scotland

Historical Context: Used in the Gilbert Scott B'lding by Prof. William Thomson in the Department of Natural Philosophy now called the Department of Physics and Astronomy - When: 1870-1899

Historical Context: Used in the Old College by Prof. William Thomson in the Department of Natural Philosophy now called the Department of Physics and Astronomy - When: circa 1867-1870

Historical Context: Event - "Lord Kelvin: A life in science" exhibition, Hunterian Museum, University of Glasgow. Object on display in this exhibition.