Historical information

The theodolite was sold by T. Gaunt & Co. of Melbourne, a manufacturer, importer and retailer of a wide variety of goods including jewellery, clocks and watches, navigational and measuring instruments, dinnerware, glassware and ornaments. Thomas Gaunt photograph was included in an album of security identity portraits of members of the Victorian Court, Centennial International Exhibition, Melbourne, 1888. (See further details below.)

History for Troughton & Simms:

Edward Troughton & William Simms established a scientific instrument making business in London in 1826.
Edward Troughton (1756-1835) had previously had his own scientific instrument business, inherited from his father. His achievement's included a transit telescope for Greenwich Observatory (1816) and the precision surveying instruments for the Ordnance Survey of Britain, Ireland and India. William Simms (1793-1860) had trained as a goldsmith and began to gain work dividing circles on fine astronomical instruments. When William Simms died in 1860, the business was taken over by his son James and nephew William.

Troughton & Simms shop in Fleet Street became the hub of the finest scientific instrument made in London, in a period in which there was an expanding demand for precision instruments, for astronomy, surveying and precision measurement. They made instruments for Greenwich Observatory, for imperial surveys and exploring expeditions. When fire destroyed the Houses of Parliament in 1834, the firm was commissioned to create new standard lengths, this required 10 years of testing against the remaining old measurements.

Troughton and Simms made several of the main instruments for Melbourne Observatory, including an 18 inch azimuth used of the Geodetic Survey, portable transit instrument (circa 1850), zenith sector (1860), a 4.5 inch equatorial telescope (1862), an 8 inch equatorial telescope (1874) spectroscope (1877) and an 8 inch transit instrument in (1884). While the firm had an excellent reputation for quality the company exasperated many of its customers with delays of years in delivering some instruments.

History for Thomas Gaunt:

Thomas Ambrose Gaunt (1829 – 1890) was a jeweller, clock maker, and manufacturer of scientific instruments, whose head office and showroom were at 337–339 Bourke Street, Melbourne, Victoria, Australia.
Thomas Gaunt established Melbourne's leading watchmaking, optical and jewellery business during the second half of the 19th century. Gaunt arrived in Melbourne in 1852, and by 1858 had established his own business at 14 Little Bourke Street. Around 1869 he moved to new premises in Bourke Street on the corner of Royal Arcade, Gaunt's shop quickly became a Melbourne institution.

Gaunt proudly advertised that he was 'The only watch manufacturer in the Australian colonies'. While many watches and clocks may have had Gaunt's name on the dial, few would have been made locally. Gaunt did make some watches for exhibitions, and perhaps a few expensive watches for wealthy individuals. Gaunt's received a telegraph signal from Melbourne Observatory each day to correct his main clock and used this signal to rate and repair ship's chronometers and good quality watches.
Thomas Gaunt also developed a department that focused on scientific instrumentation, making thermometers and barometers (from imported glass tubes), telescopes, surveying instruments and microscopes.

Significance

Significance:
With the rapid urban expansion, one of the most important needs of the new colony was to survey and map the landscape of the Australian Colony’s interior. Theodolites, such as this one, made by Troughton and Simms, who were significant scientific instrument makers of the 19th century were instrumental to the colony's surveyors and would have played an important part in their everyday work.
This transit theodolite remains of national significance due to its pioneering role in Australian science and its association with Australia's earliest surveyors and astronomers. It is also significant for its association with nineteenth-century surveying instruments and instrument makers.

Physical description

Theodolite, Vernier repetition theodolite with enclosed horizontal circle (of about 130 mm diameter). Vertical circle exposed and somewhat corroded (diameter about 115 mm). Plate level 20" per division. Altitude bubble 20" per division. Horizontal and vertical circle intervals 20". Original (blue/grey) paint. Altitude bubble setting screw disabled. Tribrach allows movement of theodolite by 15 mm inside tribrach (for centering).

Inscriptions & markings

Inscribed on the inner mounting plate,“Specially made in England for T Gaunt & Co Melbourne” and inscribed a little lower “Troughton & Simms London”