William Thomson described a new "Marine Azimuth Mirror" at the 1877 meeting of the British Association for the Advancement of Science, and patented the design in Britain and the U.S. This instrument is an example of the improved design, with a reflecting prism in place of the original mirror. Thomson introduced this form in the early 1880s. The signature indicates that it was made during the period 1900-1913. A child prodigy, William Thomson went to university at the age of eleven. At twenty-two he was appointed Professor of Natural Philosophy in Glasgow where he set up the first physics laboratory in Great Britain and proved an inspiring teacher. He primarily researched thermodynamics and electricity. On the practical side he was involved in the laying of the Atlantic telegraph cable. He was also the partner of a Glasgow firm that made measuring instruments from his own patents.An instrument of significant importance which made marine navigation easier and more accurate in the early twentieth century.An Azimuth mirror with wooden box.Kelvin & Hughs Ltd Serial No - illegible Made in Great Britainazimuth mirror, william thompson, lord kelvin, naviagtion, marine instruments