this article in Dutch.)
by Alexander Adie:
an unusually short 'barometer' without mercury.
By: Marco Fontijn.
On December 27th in 1831, warship HMS Beagle set sail from Devonport in
England under the command of Captain Robert Fitzroy (1805-65). The ship
had embarked upon an expedition of discovery around the world that was to
take five years. Fitzroy, not only a renowned captain and navigator, but
also a most Biblically oriented young man, was convinced that this
expedition would provide scientific evidence of the intrinsic truth of the
Book of Genesis. However, contrary to Fitzroy's expectations, the opposite
actually proved to be the case. For, with him was 26-year-old
biologist/geologist, Charles Darwin (1809-82).
On November 15th 1835 the ship weighed anchor off one of the Galapagos
Islands. There, during the course of Darwin's studies, it emerged that
there existed an incredible variety of finches, distinguishable by
differences in the shape of their beaks. According to Fitzroy's
Creationist beliefs, God must have been particularly interested in finches
as he had created such a variety of beaks for them in the archipelago.
Interestingly, he had created a different type especially for each island.
Yet Darwin's conclusion was a far more straightforward one: although
related, the beaks of the finches in each location were adapted to the
kind of food that was available there, according to principles of natural
After many years of research, Darwin published: 'On the Origin of Species
by Means of Natural Selection, or the Preservation of Favoured Races in
the Struggle for Life' in November 1859. Predictably, Fitzroy, by this
time a Rear Admiral, was very unhappy with this publication. He must have
been particularly dismayed to have indirectly contributed to a school
theory directly opposed to biblical doctrine. In 1860, unable to suppress
his outrage, he disrupted a lecture on Darwin's theory. Waving a Bible he
loudly exclaimed: "This is against God's word". Five years later, perhaps
in despair, Fitzroy committed suicide, an act explicitly forbidden by his
Fitzroy, however, is known to have been far less conservative in his
attitudes regarding other scientific and ethical matters. In 1845, after
two years service as Governor General of New Zealand, he was recalled to London
after upsetting the colonists by refusing to support settlers in their
attempts to dispossess Maoris of their land. He was also a notable pioneer
in the field of meteorology. After retiring from active service in the
navy he was made director of the newly established 'Meteorological
Department of the Board of Trade' - nowadays known as the 'British
Meteorological Office'. He established daily weather forecasts, set up the
first storm-warning service and published: 'the Weather Book', in 1862.
Photo 1: English Sympiesometer circa 1840.
Inscribed: 'PATENT C. Cummins 148 Leadenhall Street LONDON'.
Since his earliest voyages, Fitzroy had been interested in
the phenomena that preceded changes in the weather and in discovering how
an understanding of these might be used for weather prediction. Needless
to say, this required a great many specialist tools. For this purpose, a
large collection of highly advanced instruments was carefully selected,
packed in sawdust-filled crates and loaded aboard the Beagle. No fewer
than 22 Chronometers were amongst the collection, which also included five
examples of a special type of 'barometer' named the sympiesometer, which
was especially favoured by Fitzroy. This relatively new invention,
precluding the use of mercury, had been specially designed for maritime
use and thoroughly tested on ships travelling in the Tropics, the Polar
Regions, and off the Scottish coast. Fitzroy, no doubt, was aware of how
successful the new sympiesometer had proven to be. In a letter from the
captain of The Isabella - one of the ships of Ross's Arctic expedition of
1820 - can be found the following quote: "The Sympiesometer is a most
excellent instrument, and shews the weather far better than the marine
barometer. In short, the barometer is of no use compared to it…in my
opinion it surpasses the mercurial barometer as much as the barometer is
superior to having none at all."
Photo 3: Scottish marine barometer with sympiesometer, circa 1860-1870.
Signed: 'Mc.GREGOR & Co GLASGOW & GREENOCK'.
Alexander Adie (1775-1858), from Edinburgh, a highly acclaimed maker of
scientific instruments, was granted a patent for his sympiesometer in 1818
and published an extensive description of it a year later. The word
'sympiesometer' is derived from 'sumpiedzein' and 'metron', the Greek
terms for compression and measurement respectively. Adie had a particular
interest in meteorological instruments and was apprentice to his uncle,
John Miller, a prominent Scottish instrument maker, becoming his partner
in 1804. Until his death, Adie practiced his trade from a variety of
locations in Edinburgh. In his 'British Patent 4323' (1818), Adie's
instrument is described as 'An improvement on the air barometer'.
Adie's sympiesometer was actually an improvement upon Robert Hooke's
thermobarometer. And, although the latter instrument had been around since
the beginning of the 18th century, few were produced during the first
|One example is that of John Patrick, a famous
English barometer maker, who described his new instrument, in an
advertisement, as: 'A Ship Barometer A Foot Long'. More unusual than its
unconventional length, was the omission of mercury as the medium for
measurements. These barometers were responsive both to air pressure and
Hooke's thermobarometer consisted of a
conventional closed alcohol thermometer, together with an open
thermometer, which had air locked into the top end of its tube. The
temperature was read from the scale beside the closed thermometer, and
used to calculate the correction that was required in order to compensate
for the effect of temperature upon the open thermometer, whose barometric
scale indicated air pressure.
Photo 2: Diagram of the sympiesometer by Alexander Adie,
A = reservoir filled with hydrogen
C = reservoir filled with coloured almond oil
MN = sliding barometric scale
OP = temperature correction scale
As previously mentioned, Adie's barometer was designed to work - more or
less - according to the same principle, as Hooke's instrument. The
compression, referred to in the instrument's name, took place in the
gas-filled reservoir, from which readings could be taken by means of
coloured liquid, in this case almond oil. Instead of using air, Adie made use of
hydrogen, which was at the other end of the tube, above the almond oil.
Adie provided his instrument with a sliding temperature correction scale,
which enabled the user to adjust the barometric scale to compensate for
the effect of temperature upon the oil-filled tube, according to the
thermometer reading. Hooke's thermobarometers had a similar sliding scale,
but Adie's instrument was much narrower, simpler, and therefore easier in
Adie's original intention had been to create a barometer that would be
easier in use and less cumbersome and fragile than existing maritime
models, which consisted of a long mercury tube. In 1829, shortly before
the famous voyage of HMS Beagle, the distinguished Scottish scientist
James Forbes gave testimony to the success of Adie's invention: "As a
marine barometer, its superiority in accuracy and utility, as well as
convenience, seems fully established".
Adie's patented sympiesometers were inscribed either with his own name and
a serial number or with the name of an agent especially appointed by him.
In its sixty years of production, over 2500 sympiesometers were
manufactured in this manner. However, Adie's patent expired after fifteen
years and from then on others started to manufacture sympiesometers. Many
versions were introduced in every conceivable size; the smallest of them a
pocket-sized one. Although sympiesometers gained considerable popularity
in the 19th century, they are now hard to come by and only found
sporadically in the antique market.
Photo 4: close-up detail of the sympiesometer, as seen
in photo 3.
Useful though it was, the sympiesometer proved to have some drawbacks.
Firstly, it was inconvenient not to be able to take an instant reading.
And, during transport, it was usually necessary to keep the instrument
upright. The relatively short lifespan of the instrument also proved a
major disadvantage. Over time, the hydrogen would gradually escape through
the oil, resulting in a loss of accuracy. In addition, the almond oil was
likely to eventually evaporate.
From around 1850 new alternatives were introduced, such as the new aneroid
barometers and a type of greatly improved mercury ship's barometer,
designed according to the 'Kew Marine' principle. Although the
sympiesometer was superseded as a sole means of weather forecasting, it
found a supplementary role alongside mercury ship's barometers, enabling a
comparison in readings between either instrument in situations where
extremely accurate observations were required.
Photograph no. 3 shows an example of a ship's barometer, provided with
supplementary sympiesometer, signed 'D. Mc. GREGOR & Co GLASGOW &
GREENOCK'. Made between 1860 and 1870, the instrument's strikingly narrow
oak case is fitted with faceted glass to protect the scale plates. The
barometer scale plates are of ivory and fitted with two rack-operated
verniers. Its mercury tube is tapered in order to prevent the mercury
surging during rough weather. The palm wood reservoir has a leather bottom
and is protected by a brass cover. It has a control screw that closes the
reservoir for the purpose of transportation.
The sympiesometer, situated below the gimbals, has a silvered brass scale plate.
Protruding through its case, on the top left, is a knurled control wheel
that enables the user to refer back to the registered reading on the
barometric scale. On the right of the case is the control used to set the
Photograph no. 1 also illustrates an unusual and fairly early
sympiesometer, by Charles Cummins, designed shortly after 1840. In the
same year, this London instrument maker was granted a patent (British
patent 8462) for a sympiesometer differing in shape from that by Adie and,
moreover, using sulphuric acid rather than almond oil. The case is of solid
mahogany and a flat glass protects the silvered brass scale plates. The
mercury thermometer measures in degrees Fahrenheit and the barometric
scale plate moves up and down by operating a brass sliding control,
mounted on the right of the case. On this slide there is a brass knob used
to set the rack-operated vernier.
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