English. Charing Cross, London. Circa 1840. Optics in the theodolites and level come to a clear focus and provide an inverted image. In British instruments of this era the image is usually inverted. To provide an upright image required an extra lens in the telescope. The user was usually sighting on a plumb bob string or levelling rod so image being inverted or upright wasn't important. Thomas Jones. Trade label marked, "Thomas Jones, Pupil of Ramsden, Astronomical and Philosophical Instrument Maker...". Height of telescope 8.5". Length of closed telescope 17.5". Level vial is cracked and dry. Retained in mahogany case with trade label. Est. $300 - 500. CODE-INST. CODE-TOOL