By Land and Sea

Instruments of Place

This display has been sponsored by The Institution of Surveyors (NSW Branch)

How do we know where we are? This is no simple matter. With the modern satellite-based Global Positioning System, we can define a position on the globe with great accuracy. It has taken centuries of patience and ingenuity to achieve this result.

Travellers have long known how to determine their latitude (north/south position). Longitude (east/west position) presented much greater difficulties and was only solved in the 18th century. The technique of lunar differences allowed longitude to be calculated on the basis of astronomical observations. A more convenient method depended on the development of the marine chronometer. This was a clock which could maintain accurate time on a rolling ship for periods of months or years. Captain Cook’s second Pacific expedition in the 1770s was the first long voyage to use marine chronometers . Local time was compared with the reference time displayed on the chronometer. For the British sailors this was the time at Greenwich. (Only in 1884 was Greenwich universally adopted as the prime meridian.)

As one hour is equivalent to 15 degrees difference in longitude, it became possible for the first time in the late 18th century for accurate maps to be produced. The quality and precision of the instruments required for determining local time by solar and stellar observations, and for charting reefs and coastlines, mountains and rivers, also improved dramatically in the late 18th century. The settlement of Australia was in part the legacy of these technological improvements.

The Institution of Surveyors

The Surveyors’ Club of N.S.W., formed in 1884, met regularly in a Sydney hotel where members read and discussed papers on the principles and practice of surveying. Later it adopted the more formal title of N.S.W. Association of Surveyors, and was incorporated in 1891 as The Institution of Surveyors, N.S.W. Similar bodies were formed in the other states. These amalgamated in 1952 as The Institution of Surveyors, Australia, which today has about 3400 members nationally.

Pillar Mounted Sextant

Sextant

A large pillar-mounted sextant such as this was used for making accurate equal-altitude observations of the sun or a star for determining local time. By comparing local time with the time of another place such as Greenwich in England, maintained on a marine chronometer, it was possible to determine longitude. Thjis was particularly important in hydrographic surveying.

Signed, "Bate London". Made and retailed by R.B.Bate about 1820
Transferred from Department of Civil Engineering, University of Sydney
MM 95/012

Aneroid Barometer

Barometers measure atmospheric pressure and so can be used to measure altitude. The aneroid barometer has a sealed metal bellows which expands or contracts by atmospheric pressure. Before its introduction in about 1850, explorers and surveyors commonly used a mercury-in-glass barometer which was large (more than one metre long), awkward to carry, easily damaged, and difficult to repair.

Retailed in Sydney by Angelo Tornaghi about 1880
Transferred from Geology and Geophysics, University of Sydney
MM 86/015

Hypsometer

The hypsometer or boiling-point thermometer also measures altitude. The temperature at which water boils decreases with altitude. A spirit lamp in the base heats a small vessel of water. The hypsometer was a convenient alternative to the mercury barometer for surveyors and field scientists but was increasingly displaced by the aneroid barometer in the later 19th century.

Transferred from Civil Engineering, University of Sydney
MM 95/026

Box Sextant

Edward Troughton devised the box sextant in about 1800. It is essentially a miniaturised sextant with the mirrors contained in a cylindrical case. Being highly portable it was widely used in land-surveying, including military surveying. This one appears to have been made for use in the First World War.

Signed, 'Troughton & Simms', 1914
Transferred from Civil Engineering, University of Sydney
MM 95/017

Solar Compass

An American surveyor, W.A. Burt, invented the solar compass in 1835. The solar attachment enabled the determination of the true meridian by solar observations. This was important where magnetic ore bodies caused a deviation in the compass. This instrument together with two surveyor’s compasses by the same maker were brought to Sydney in the 1890s.

Signed 'JOHN ROACH / Maker / SAN FRANCISCO', made about 1890
Transferred from Civil Engineering, University of Sydney
MM 95/020

Transit Theodolite

Theodolite

The theodolite is a precision instrument for measuring horizontal and vertical angles. For most surveying purposes a theodolite with a horizontal circle up to 6 inches in diameter was sufficient. Larger instruments such as this 8-inch theodolite were useful for surveying over large areas. Troughton and Simms were leading makers of a wide range of precision instruments throughout the 19th century.

Signed, 'TROUGHTON & SIMMS / LONDON', made about 1900
Transferred from Civil Engineering, University of Sydney
MM 80/001/6

Dumpy Level

This type of level has a telescope perpendicular to its axis of rotation. Used in conjunction with a staff, precise differences between the level of two or more positions on the ground can be determined.

Signed 'Stanley Gt Turnstile Holborn London W.C.', number 8272, about 1900
Transferred from Civil Engineering, University of Sydney
MM 80/001/3

Circumferentor or Surveyor’s Compass

Used with a chain, the circumferentor provided a relatively quick method of surveying but not with the accuracy of a theodolite. This circumferenter has a scale for adjusting the compass box for local magnetic variation. Why are East and West reversed? Look at the alignment of the sighting vanes in relation to the position of the magnetic needle.

Signed 'F. Street, Commercial Road, Lambeth, LONDON'
Retailed in Sydney by Brush and MacDonnell about 1860
Transferred from Civil Engineering, University of Sydney
MM 95/018

Circular Protractor

tornaghi.jpg

Protractors were used by draftsmen in numerous technical disciplines such as mapping, engineering and architecture to measure or lay out angles on charts and diagrams. Some protractors had additional features such as a moveable arm and vernier scale for greater accuracy.

Retailed in Sydney by Angelo Tornaghi about 1870
MM 95/009

Surveyor’s Cross

When mounted on a tripod or staff fixed into the ground, the surveyor’s cross was used to lay out right angles.

Late 19th century
Transferred from Civil Engineering, University of Sydney
MM 95/023

Professional Training

Survey map

Originally the main road into the University of Sydney was a straight carriageway through what is now Victoria Park. This is shown in the plan drawn as a student exercise by William Henry Ledger in 1892. Ledger graduated the following year as a Bachelor of Engineering. Surveying has been taught at the University of Sydney since the introduction of Engineering in 1883.
University of Sydney Archives