Man In Suit

Source: Royal Society of Chemistry

Clarke Hydrometer

Circa 1755, Clarke Hydrometer , 22 screw-on weights in mahogany case
Found at: 

wooden box

This plaque appears on the outside cover of the WHP Sikes’ Hydrometer storage box
Photo by Cindy Lambert


This label appears on the underside of the WHP Sikes’ Hydrometer storage box
Photo by Cindy Lambert

The science series of the Wine History Project continues with an article about the hydrometer, and specifically the Sikes’ hydrometer that is part of our important collection of objects of all things related to wine. This is the third object to be researched of the six object which we have collected relating to enology.

Even though I can find reference to Galileo mentioning the hydrometer in his work from 1612, the industrial development in Europe propelled the need for the hydrometer. This was first because of the alcohol taxation and public controversy being used in the distillation industry to measure alcohol content and determining excise taxes in England.

Oenology is an English word which is derived from the Greek word oinos, or wine, and the suffix – logia, is for the “study of”.

What is a Hydrometer?

In 1669, Robert Boyle supported the use of glass bulbs to measure the densities of liquids. Then in the 1770s, Daniel Fahrenheit proposed a new design of the hydrometer that would allow the density of any liquid to be determined. The rod projecting from the top now bore only a single mark. After weighing the device dry, it was floated with weights added to the dish until it floated with the mark level with the water. The procedure was repeated then the device was immersed in the test liquid. The ratio of the two weights gave the density.

William Nicholson  (born in London, 1753- died in London 1815) was at various times a hydraulic engineer, inventor, translator, a mathematics teacher, a scientific publicist., and ran several coffee houses where he met many of the leading philosophers of the time. He developed an improved hydrometer, an instrument for measuring the density of liquids in 1790. He combined the Boyle and Fahrenheit approaches. His device was equipped with a dish at the top and a basket at the bottom. The basket could be loaded with a known mass of unknown solid and by adjusting the weights at the top gave the weight of the displaced water, from which the density of the solid was calculated.

Clarke Hydrometer

John Clarke invented an instrument to ascertain the true strength of proof of brandy, rum, malt, or molasses spirits, without tasting the same in 1746. It measured the specific gravity of liquids by the flotation principle. Clarke hydrometers were adopted by the Excise in 1762 in order that strength as well as volume could be ascertained. The Clarke type of hydrometer was not considered sufficiently accurate by the end of the century. The thermometer scales read from “coldish” to “very hot”. Sikes’ hydrometer replaced these as they were made superior, and the thermometer was numerically based.

Who was Bartholomew Sikes?

Bartholomew Sikes (unknown– 1803) was a British excise officer who recognized problems with the Clarke hydrometer then in use. In 1802 the Board of Excise held a competition to find a better instrument than Clarke’s hydrometer for revenue purposes and nineteen instruments were submitted for consideration.

The winning design was that of Bartholomew Sikes, who was an employee of the Excise Commissioners. The Sikes hydrometer was used to determine the strength of spirits for the distiller, winemaker, and tax collector. It was required that brewers notify the tax exciseman of time when the first wort would be ready for measure. The exciseman would measure the gravity of the wort and impose the duty due.

His proposed design was enshrined in legislation in 1816 with the Sikes Hydrometer Act of 1816. From 1816 until 1980 the hydrometer was the standard used in the UK to measure the alcohol proof of spirits, and from 1846 in Canadian law. 

The Sikes’ Hydrometer was for many years the standard means for determining the alcohol content of beers and spirits and from that the duty payable on that content.

Definition: the unfermented or fermenting infusion of malt that after fermentation becomes beer or mash.

The successor to Sike was Thomas O’Dempsey Buss (1847-1883)

Who was Joseph Long?

Long’s nationality was British, and from what I can find out in my research he was known to be a mathematical instrument maker, an optical instrument maker, and a hydrometer instrument maker.

This instrument maker began in business at 20 Little Tower Street (1821-1884). in London, England. The business moved locations to 43 EastCheap (1885-1936).

Why a Winemaker Uses a Hydrometer

The hydrometer is used by winemakers and brewers alike as an essential piece of testing equipment. Usually, it is made of blown glass, with a weighted, bulbous bottom and a long narrow stem. There is used in conjunction a tall, thin measuring cylinder which contains the liquid.

Here are the reasons I have found why a winemaker might want to use a hydrometer.

  • To measure the amount of natural sugar present in a wine or must
  • To estimate the potential alcohol percentage at time of yeast addition
  • To measure the specific gravity of a must or wine
  • To determine the progress of fermentation
  • To calculate the percentage of alcohol conversion during fermentation by using the before and after readings
  • To enable accurate calculations to be made when increasing the alcohol percentage artificially
  • To allow the winemaker to determine when fermentation has completed or at what stage it should be stopped

Most of the research about the hydrometer mentioned how important it is for hydrometers to be cleaned, sanitized, and treated gently.

The Wine History Project Hydrometer

This 19th century Sikes hydrometer set is in good condition and manufactured by Joseph Long at the 43 East Cheap London address. The weights are all individually marked with the maker’s initials ‘JL’ and the serial number is 24969. The bone backed thermometer also carries the maker’s name. The instrument is housed in a mahogany case with velvet lining. A deluxe version would have included two beautifully crafted bone proof rules.

Sikes’ Hydrometer

WHP  I.D.# 

Object Name: 


Patent for WHP hydrometer: 

Manufactured by Joseph Long:  

Hydrometer original patent: 

Obtained by WHP: 



Sikes’ Hydrometer

Bartholomew Sikes

Circa 1802

According to label on box, 1926

1790, William Nicholson


Mahogany box, brass, bone, glass

old photo of people and a building

In Conclusion

This series will continue with details and explanations about the inventors, distributors, and history behind the other enological objects in the Wine History Project of San Luis Obispo County Collections. The Wine History Project has a large collection of artifacts used during 19th and 20th centuries in the vineyards and winemaking. If you wish to make a donation to our collection, please contact Cynthia Lambert at 

Stay tuned for the next article in the series when I fill you in on a Soil Test Kit and Frank Linton LaMotte, a Lacrosse player for Johns Hopkins University in Baltimore, Maryland.


Information was found at The Science Museum Group who cares for an astonishingly diverse and internationally significant collection of 7.3 million items from science, technology, engineering, medicine, transport, and media. 

These objects, they say, tell the story of our world; from the rise of the Indus Valley civilization over 3,000 years ago to the microchips powering our connected planet today. Their project, they say, will dramatically improve public access to many thousands of historic items, enabling one to explore more of the collection which dates to its origin to the 1851 Great Exhibition of the Works of Industry of All Nations which took place in the United Kingdom (1May-15 October 1851).

National Museum of American History at Behring Center
Part of the Smithsonian Institution
Constitution Avenue, NW
Between 12th and 14th Streets
Washington, D.C.
The collection is approximately 1.7 million objects and 22,000 linear feet of archival documents. The online catalog of their collection is a work in progress to accurately describe their objects and documents and place them in their historical context(s).

National Maritime Museum
Category: Experimental Chemistry

Chemistry World
Opinion article by Andrea Sella, 17 December 2018