This early example of a transit theodolite was made for the U. S. Coast Survey in the 1840s. The "Thomas Jones, 4 Rupert St London" inscription refers to Thomas Jones (1775–1852), an instrument maker who worked for Jesse Ramsden, and who was elected a Fellow of the Royal Society of London in 1835.The horizontal and vertical circles are silvered, and read by verniers and magnifiers to 30 seconds.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550–1851 (London, 1995), p. 154.
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.
If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.