Editing Barometer (section)

=== Marine Barometer ===
The need for a practical marine barometer arose from the urgent necessity of weather prediction at sea, where sailors faced frequent, and often dangerous, changes in wind, calm, and storm conditions.<ref name=":3" /> Traditional mercury barometers, though useful on land, proved unreliable on ships due to their susceptibility to the ship’s motion.<ref name=":3" /> Oscillations caused the mercury to strike the top of the glass tube, leading to frequent breakage and making air pressure readings nearly impossible to interpret accurately during voyages.<ref name=":3" />

[[Roger North (biographer)|Roger North]] observed that many, including [[Robert Hooke]], attempted to resolve these issues but often abandoned the endeavor due to technical limitations.<ref name=":3" /> Nonetheless, Hooke remained persistent, proposing several adaptations including narrowing the open end of the siphon tube and exploring spiral tube designs.<ref name=":3" /> His most notable contribution was the creation of a double thermometer marine barometer, also referred to as a manometer, which was presented to the [[Royal Society]] in 1668 and constructed by Henry Hunt.<ref name=":3" />

Hooke’s marine barometer marked a turning point in the development of nautical meteorological tools. It featured a compact, affordable design tailored for maritime use, becoming the first instrument specifically constructed for sailors.<ref name=":3" /> The device combined a sealed spirit thermometer with an open air-based thermometer, calibrated to reflect barometric pressure changes through liquid displacement<ref name=":12">{{Cite journal |last=Halley |first=Edmund |date=1683–1775 |title=An Account of Dr Robert Hook's Invention of the Marine Barometer |journal=Philosophical Transactions |volume=22 |pages=791–794 |doi=10.1098/rstl.1700.0074 |jstor=}}</ref><ref name=":4">{{Cite web |date=2025-02-02 |title=Torricelli and the Ocean of Air: The First Measurement of Barometric Pressure - PMC |url=https://pmc.ncbi.nlm.nih.gov/articles/PMC3768090/ |access-date=2025-03-21 |website=web.archive.org |archive-date=2025-02-02 |archive-url=https://web.archive.org/web/20250202182642/https://pmc.ncbi.nlm.nih.gov/articles/PMC3768090/ |url-status=bot: unknown }}</ref>. Hooke’s use of hydrogen-filled containers and colorful almond oil further enhanced visibility and responsiveness.<ref name=":32">{{Cite journal |last1=Ward |first1=Catharine |last2=Dowdeswell |first2=Julian |date=August 2006 |title=On the Meteorological Instruments and Observations Made during the 19th Century Exploration of the Canadian Northwest Passage |journal=Arctic, Antarctic, and Alpine Research |volume=38 |issue=3 |pages=454–464 |doi=10.1657/1523-0430(2006)38[454:OTMIAO]2.0.CO;2 |jstor=}}</ref> Notably, [[Edmond Halley|Edmund Halley]] tested this prototype on his South Atlantic voyage from 1698 to 1700 and praised its reliability in forecasting weather changes.<ref name=":3" /><ref name=":12" /> His endorsement led to greater interest and validation by the Royal Society.<ref name=":3" /><ref name=":12" /> Figure 8 below is from this report, depicting the Hooke Barometer, with detailed description in the writing.<ref name=":12" />

[[File:Stick Barometer.png|thumb|Figure 8 from Robert Hooke's Barometer Invention|left|455x455px]]

Building on Hooke’s foundation, John Patrick sought to improve the design by replacing the water with mercury, advertising his version as a “new marine barometer.”<ref name=":3" /> Though some criticized it for the difficulty of reading the mercury column due to shipboard vibrations, navigator [[Christopher Middleton (navigator)|Christopher Middleton]] employed it during expeditions to Hudson's Bay.<ref name=":3" /> He consistently found it effective in forecasting storms, wind changes, and even the proximity of ice.<ref name=":3" />

A significant advancement occurred during [[James Cook|Captain James Cook]]’s renowned voyages in the late 18th century.<ref name=":3" /> As part of preparations for Cook’s second Pacific expedition (1772–1775), the Board of Longitude and the Royal Society commissioned the production of marine barometers.<ref name=":3" /> Renowned instrument maker [[Edward Nairne]] was chosen to supply the equipment.<ref name=":3" /> Contrary to expectations for spiral tubes, Nairne opted for straight, constricted tubes mounted on boards, coupled with a gimbaled suspension system to ensure vertical orientation and stability at sea.<ref name=":3" />

Nairne’s design represented a leap in functionality. The narrow bore significantly reduced mercury motion, enabling more accurate readings even in turbulent conditions.<ref name=":3" /> These instruments proved so reliable that they were adopted not only by the [[Royal Navy]] but also by international expeditions.<ref name=":3" /> The [[East India Company]], Russian explorers, and French and Spanish navigators, including [[Jean-François de Galaup, comte de Lapérouse]] (voyage in 1785) and [[Alejandro Malaspina|Alessandro Malaspina]] (voyage in 1789), incorporated variants of Nairne’s barometer into their voyages.<ref name=":3" />

Despite the widespread use of Nairne’s marine barometer, it was not without limitations.<ref name=":13">{{Cite journal |title=1944JRASC..38...41K Page 41 |url=https://adsabs.harvard.edu/full/1944JRASC..38...41K |access-date=2025-03-21 |journal=Journal of the Royal Astronomical Society of Canada|bibcode=1944JRASC..38...41K |last1=Knowles Middleton |first1=W. E. |date=1944 |volume=38 |page=41 }}</ref> Lapérouse lauded the device’s predictive capabilities but also noted inconsistencies in mercury behavior, highlighting the complexity of translating instrument readings into reliable forecasts.<ref name=":13" /> In response to the fragility of glass tubes, other scientists, such as Le Roy, proposed alternate models like the folded Huygens barometer, designed for enhanced durability and reduced oscillation aboard ships.<ref name=":13" />

The marine barometer’s practical value was reaffirmed in 1801 when the [[Royal Society]] sent Captain [[Matthew Flinders]] on a three-year voyage from New Holland to New South Wales, equipped with one of Nairne’s barometers.<ref name=":22">{{Cite journal |last=Flinders |first=Matthew |date=1806 |title=Observations upon the Marine Barometer |journal=Philosophical Transactions of the Royal Society of London |volume=96 |pages=239–266 |jstor=}}</ref> In his official correspondence, Flinders confirmed the instrument’s success and expressed appreciation for its stability and precision in recording atmospheric conditions.<ref name=":22" />

Throughout its evolution, the marine barometer transitioned from a theoretical invention to a critical navigational and meteorological tool. Its development not only reflected ingenuity in overcoming the challenges of shipboard instrumentation but also underscored its importance in the broader context of global exploration. These devices empowered mariners to make informed decisions, contributing to safer and more efficient voyages across the world's oceans.  

==== Wheel barometers ====
A wheel barometer uses a "J" tube sealed at the top of the longer limb.  The shorter limb is open to the atmosphere, and floating on top of the mercury there is a small glass float.  A fine silken thread is attached to the float which passes up over a wheel and then back down to a counterweight (usually protected in another tube).  The wheel turns the point on the front of the barometer.  As atmospheric pressure increases, mercury moves from the short to the long limb, the float falls, and the pointer moves.  When pressure falls, the mercury moves back, lifting the float and turning the dial the other way.<ref>{{cite web|last=Hood|first=Jean|title=Barometers : History, working and styles|date=5 December 2017|url=http://www.jeanhood.co.uk/barometers_history_and_styles_etc.html|access-date=21 June 2020}}</ref>

Around 1810 the wheel barometer, which could be read from a great distance, became the first practical and commercial instrument favoured by farmers and the educated classes in the UK. The face of the barometer was circular with a simple dial pointing to an easily readable scale: "Rain - Change - Dry" with the "Change" at the top centre of the dial. Later models added a barometric scale with finer graduations: "Stormy (28 inches of mercury), Much Rain (28.5), Rain (29), Change (29.5), Fair (30), Set fair (30.5), very dry (31)".

Natalo Aiano is recognised as one of the finest makers of wheel barometers, an early pioneer in a wave of artisanal Italian instrument and barometer makers that were encouraged to emigrate to the UK. He listed as working in Holborn, London {{circa|1785}}–1805.<ref>{{cite web |title=Natalo Aiano |url=https://www.aianos.co.uk/about-us/ |website=About us page |date=22 May 2017 |publisher=C. Aiano & Sons Ltd.}}</ref> From 1770 onwards, a large number of Italians came to England because they were accomplished glass blowers or instrument makers. By 1840 it was fair to say that the Italians dominated the industry in England.<ref>{{cite book |last1=Nicholas |first1=Goodison |title=English barometers 1680–1860 : a history of domestic barometers and their makers and retailers |date=1977 |publisher=Antique Collectors' Club |isbn=978-0902028524 |edition=Rev. and enl.}}</ref>