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Hilger & Watts Ltd., England



Serial Number



Telescope Length 200 mm, Height 340 mm


Hilger & Watts Vernier Theodolite


This is a Vernier Theodolite typically used in mining and consists of a vernier reading system for the horizontal and vertical circles instead of an optical micrometer system. The circles are equipped with magnifying glasses attached at opposite ends of each circle for more comfortable vernier reading. The horizontal circle can be read to 0.1' using the vernier. The instrument consists of: (1) a levelling head which supports the main working parts of the instrument and is capable of being screwed onto a tripod, (2) a lower circular horizontal metal plate with a silver vernier graduation, (3) an upper circular horizontal plate, (4) a vertical circle with vernier graduations and (5) a telescope with the altitude plate bubble attached beside the vertical circle.

The diameter of the vertical circle is 110 mm and the horizontal circle diameter is 149 mm. Both the horizontal and vertical circles are enclosed to prevent damage from dust and grime.  The telescope has low magnification but incorporates a wide field of view.

According to T. Garver the scales read typically to 20".

History & comments

The vernier is an auxiliary graduation, placed alongside the main one with the purpose of determining fractions of the graduation unit. The vernier is typically used with theodolites of medium or low accuracy, as well as for simple angle measuring devices.

According to T. Garver, Adam Hilger and E. R. Watts & Son merged in 1948. In consequence, this instrument was manufactured later than that.


In a wooden box




  • Theodolite comes with several accessories including dark eyepieces, a wrench set, a brush and a plumb bob. 
  • Instrument donated by the Mining Department of UNSW.
  • Thanks to T. Garver for providing additional information on the manufacturer and the instrument.
  • Catalogued by T. Ko.
  • Updated by F. Pall & J. M. Rüeger.


Manufactured after 1948. Catalogued in 1997 & 2005.

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