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2010/1/185 Sikes hydrometer, with case, for measuring density of liquids, brass / glass / wood / fabric / bone, made by J J Hicks, 8-10 Haton Garden, London, England, 1885-1899. Click to enlarge.

Sikes hydrometer for measuring density of liquids

Made by Hicks, J. J. in London, Greater London, England, United Kingdom, Europe, 1875-1899.
This object is a particularly nice hydrometer with the two rules that would have made it a deluxe version in the liquor trade. It is part of a collection relating to the history and development of calculating devices assembled by Assoc Professor Allan Bromley of Sydney University, comprising mathematical instruments, slide-rules, mechanical and electronic calculators, electronic analogue computers, computer components, kit computers, education computers, and associated ephemera.

Allan Bromley was a lecturer and researcher at the University of Sydney Basser Department of Computer Science from 1978 until his untimely death in August 2002. He specialised in Computer Architecture, Computer Logic and in particular the History of Computing. He was regarded as the world authority on Charles Babbage's Calculating Engines (instigating the building of the Difference Engine No.2 at the Science Museum London) and the Ankithera Mechanism and had extensive knowledge of calculators, analogue computers, logic, stereopsis, totalisators, clocks and time keeping and mechanical engineering.


Object No.


Object Statement

Sikes hydrometer, with case, for measuring density of liquids, brass / glass / wood / fabric / bone, made by J J Hicks, 8-10 Haton Garden, London, England, 1885-1899

Physical Description

The Sikes hydrometer is a brass instrument consisting of a thermometer, flotation sphere, two rulers and nine weights, all housed in a wooden case. It was used in conjunction with the book of tables by distillers to determine the strength of spirits by providing the user with alcohol proof, strength and percentages.

The thermometer is made is made up of bone base, engraved on one side with a temperature scale from '30:100" degrees. Mounted on the base using three metal brackets, and running along the scale, is a cylindrical glass tube filled with mercury. A engraving on the right hand side reads, 'T.O. BLAKE (SIKES HYDROMETERS) LTD'.

The flotation sphere is made from brass and consists of a rectangular bar, with graduated scale on both sides, followed by a large spherical ball and a cylindrical tail or stem, which is used to house additional weights when making measurements. The floatation sphere is engraved on the side with, 'No 14642 SIKES P51 degrees'

The wooden case is rectangular and has a brass hinged lid, with two clasps at the front. A cream coloured inlay square is used to decorate the top of the lid, while an inlay plaque in the centre reads, 'SIKES HYDROMETER / J.J. HICKS / 8, 9 & 10 HATON GARDEN / LONDON. ENG.'.The interior of the case is lined with a dark red felt, while the lid's interior is cushioned and lined with a light red silk. The case contains a number of sectioned compartments for each component of the hydrometer and ten small bone knobs in the centre are used to secure the weights and cap.

The two wooden rulers used in conjunction with the device are duplex models each containing three scales and two meal bands on each end. The first is known as the comparative rule, and features 'OVER PROOF' on the obverse side and 'PROOF UNDER PROOF' & 'THERMOMETER SCALE' on the reverse side. The second is the proof rule and has 'PROOF' on both the obverse and reverse sides. Both rules are engraved on the edge with, 'J. J. HICKS 8. 9 & 10 HATON GARDEN LONDON'

The nine weights, described as 'extra masses', for the hydrometer are all donut shaped, with one side cut out for attachment to the spherical bob. Each one varies in size and weight ranging from '90' to '20' and are engraved with the weight amount on the top. Along with the weights the device also has a small cylindrical brass cap with an internal thread.

Accompanying the hydrometer is a brown, leather bound, book containing basic instructions on the use of the Sike's hydrometer, as well as a series of graphs and table to assist with calculating 'concentrated strength' and 'specific gravity' of liquids. The books cover and back is decorated with an imprinted pattern in the corners, and gold lettering in the cover's centre reads, 'HYDROMETER / TABLES'. It is signed on the inside of the cover, 'Allan F Bromley / 23-3-90 / (1990-3)'



Mfr: J.J. Hicks, 8, 9 & 10 Hatton Garden, London



The plan commonly adopted to obviate the necessity of inconveniently long stems is to construct a number of hydrometers as nearly alike as may be, but to load them differently, so that the scale-divisions at the bottom of the stein of one hydrometer just overlap those at the top of the stem of the preceding. By this means a set of six hydrometers, each having a stem rather more than five inches long, will be equivalent to a single hydrometer with a stem of thirty belies. But, instead of employing a number of instruments differing only in the weights with which they are loaded, we may employ the same instrument, and alter its weight either by adding mercury or shut to the interior (if it can be opened) or by attaching weights to the exterior. These two operations are not quite equivalent, since a weight added to the interior does not affect the volume of liquid displaced when the instrument is immersed up to a given division of the scale, while the addition of weights to the exterior increases the displacement. This difficulty may be met, as in Keene's hydrometer, by having all the weights of precisely the same volume but of different masses, and never using the instrument except with one of these weights attached.

Sikes's hydrometer was established for the purpose of collecting the revenue of the United Kingdom by Act of Parliament, 56 Geo. III. c. 140, by which it was enacted that "all spirits shall be deemed and taken to be of the degree of strength which the said hydrometers called Sikes's hydrometers shall, upon trial by any officer or officers of the customs or excise, denote such spirits to be.
Above reference accessed 14/06/16 by Nina Earl


Credit Line

Donated through the Australian Government's Cultural Gifts Program in memory of Associate Professor Allan Bromley, 2010

Acquisition Date

20 January 2010

Cite this Object


Sikes hydrometer for measuring density of liquids 2020, Museum of Applied Arts & Sciences, accessed 11 July 2020, <>


{{cite web |url= |title=Sikes hydrometer for measuring density of liquids |author=Museum of Applied Arts & Sciences |access-date=11 July 2020 |publisher=Museum of Applied Arts & Sciences, Australia}}

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