Description: Closest packing model.

Caption: The 'pebbles' are based on simple pyramids and were supposed to represent the internal structure of the 'ether' as a substance that required to be perfectly inelastic and therefore extremely dense. Kelvin intended them to represent this dense medium.

Introduction: Made by Lord Kelvin these ten primitive tetrahedrons were used to demonstrate a molecular closest packing model. For a discourse on light and its interactions with the 'ether', Kelvin combined his pitch pool experiment (see GLAHM 113456) with this 'pebble' model.

Background: He revised the structure of the ether in 1887 when he designed the 'bedspring model'. (see GLAHM 113643). Kelvin had largely abandoned the theory of the 'ether' by the early eighteen nineties calling the experience "fifty years of ether dipsomania". Although his theories on light were ultimately wrong his practice of making models, to represent physical processes, has become standard practice in all branches of science and engineering across the world.

Reference: Thomson, William Lord, 1st Baron Kelvin of Largs. "Baltimore Lectures on molecular dynamics and the wave theory of light", 1904 p. 628

Historical Context: Design - 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: Designed by Kelvin - When: 1884 - Where: Netherhall, Largs, Ayrshire, Scotland

Historical Context: Made by Kelvin - When: 1887 - Where: Scotland

Historical Context: Manufacture - 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 Gilbert Scott Buildings in research and 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 research and teaching of Natural Philosophy - Where: Natural Philosophy Lecture Theatre, Gilbert Scott Building, University of Glasgow, University Avenue, 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: 1887

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