Thomas Stevenson
PRSE
The Royal Society of Edinburgh (RSE) is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was establis ...
MInstCE FRSSA FSAScot (22 July 1818 – 8 May 1887) was a pioneering Scottish
civil engineer
A civil engineer is a person who practices civil engineering – the application of planning, designing, constructing, maintaining, and operating infrastructure while protecting the public and environmental health, as well as improving existing i ...
,
lighthouse
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways.
Ligh ...
designer and
meteorologist
A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmosphere of Earth, atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists ...
, who designed over thirty lighthouses in and around Scotland, as well as the
Stevenson screen
A Stevenson screen or instrument shelter is a shelter or an enclosure used to protect meteorological instruments against precipitation and direct heat radiation from outside sources, while still allowing air to circulate freely around them. It f ...
used in meteorology. His designs, celebrated as ground breaking, ushered in a new era of lighthouse creation.
He served as president of the
Royal Scottish Society of Arts
The Royal Scottish Society of Arts is a learned society in Scotland, dedicated to the study of science and technology. It was founded as The Society for the Encouragement of the Useful Arts in Scotland by Sir David Brewster in 1821 and dedicate ...
(1859–60), as president of the
Royal Society of Edinburgh
The Royal Society of Edinburgh (RSE) is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was establis ...
(1884–86), and was a co-founder of the
Scottish Meteorological Society
The Scottish Meteorological Society was founded in 1855 by David Milne-Home with private funding, particularly from wealthy landowners who wished to compile meteorological records in order to improve agriculture.
The Society founded the observat ...
.
He was the father of writer
Robert Louis Stevenson
Robert Louis Stevenson (born Robert Lewis Balfour Stevenson; 13 November 1850 – 3 December 1894) was a Scottish novelist, essayist, poet and travel writer. He is best known for works such as ''Treasure Island'', ''Strange Case of Dr Jekyll ...
.
Life and career
He was born at 2 Baxters Place in
Edinburgh
Edinburgh is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. The city is located in southeast Scotland and is bounded to the north by the Firth of Forth and to the south by the Pentland Hills. Edinburgh ...
, on 22 July 1818, the youngest son of engineer
Robert Stevenson Robert, Rob, or Bob Stevenson may refer to:
* Robert Stevenson (civil engineer) (1772–1850), Scottish lighthouse engineer
* Robert Louis Stevenson (1850–1894), Scottish writer ("Treasure Island"), grandson of lighthouse engineer Robert Stevenso ...
, and his wife (and step-sister) Jean Smith. He was educated at the Royal High School in Edinburgh.
Thomas Stevenson was a devout and regular attendee at St. Stephen's Church in
Stockbridge, at the north end of St Vincent Street, Edinburgh.
He lived with his family at Baxters Place until he got married in 1848. He then got a house at 8 Howard Place. By 1855 he moved to 1 Inverleith Terrace. From at least 1860 he lived at 17
Heriot Row
Heriot Row is a highly prestigious street in central Edinburgh, virtually unchanged since its original construction in 1802. From its inception to the present day in remained a top address in the city and has housed the rich and famous of the ci ...
, a large Georgian terraced townhouse in
Edinburgh's New Town.
In 1864, he published ''The design and construction of harbours: a treatise on maritime engineering''. The book was based on an article he had originally written for the
Encyclopædia Britannica
The is a general knowledge, general-knowledge English-language encyclopaedia. It has been published by Encyclopædia Britannica, Inc. since 1768, although the company has changed ownership seven times. The 2010 version of the 15th edition, ...
, and covered the principles and practices involved in
harbour
A harbor (American English), or harbour (Commonwealth English; see American and British English spelling differences#-our, -or, spelling differences), is a sheltered body of water where ships, boats, and barges can be Mooring, moored. The t ...
design and construction. The work discussed the
geological
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...
and physical features affecting harbour design, the generation and impact of
waves
United States Naval Reserve (Women's Reserve), better known as the WAVES (for Women Accepted for Volunteer Emergency Service), was the women's branch of the United States Naval Reserve during World War II. It was established on July 21, 1942, ...
, along with construction materials and
masonry
Masonry is the craft of building a structure with brick, stone, or similar material, including mortar plastering which are often laid in, bound, and pasted together by mortar (masonry), mortar. The term ''masonry'' can also refer to the buildin ...
types for
quay walls. The book also explored the efficacy of
tides
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide tables ...
and
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...
in maintaining
outfalls. A second edition of the book was published in 1874.
In 1869, as a successful experiment into using the newly invented
electric light
Electric light is an artificial light source powered by electricity.
Electric Light may also refer to:
* Light fixture, a decorative enclosure for an electric light source
* Electric Light (album), ''Electric Light'' (album), a 2018 album by James ...
for
lighthouses
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways.
Lighthouses mark ...
, Stevenson had an underwater cable installed from the eastern part of
Granton Harbour, and a light on the end of the
Trinity Chain Pier
Trinity Chain Pier, originally called Trinity Pier of Suspension, was built in Trinity, Edinburgh, Scotland in 1821. The pier was designed by Samuel Brown (Royal Navy officer), Samuel Brown, a pioneer of chains and suspension bridges. It was int ...
was controlled from half a mile away by an operator on the harbour. He designed the
Stevenson screen
A Stevenson screen or instrument shelter is a shelter or an enclosure used to protect meteorological instruments against precipitation and direct heat radiation from outside sources, while still allowing air to circulate freely around them. It f ...
as a shelter to shield
meteorological
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture ...
instruments, and this has been widely adopted.
He died at 17 Heriot Row in
Edinburgh
Edinburgh is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. The city is located in southeast Scotland and is bounded to the north by the Firth of Forth and to the south by the Pentland Hills. Edinburgh ...
on 8 May 1887 and is buried in the Stevenson family vault in
New Calton Cemetery
New Calton Burial Ground is a burial ground in Edinburgh. It was built as an overspill and functional replacement to Old Calton Burial Ground and lies half a mile to its east on Regent Road in Edinburgh, Scotland, on the south-east slopes of Ca ...
. The vault lies midway along the eastern wall.
Stevenson's formula for the prediction of wave heights
In the course of his work as a lighthouse and harbour engineer, Stevenson had made observations of
wave heights
In fluid dynamics, the wave height of a surface wave is the difference between the elevations of a crest and a neighboring trough. ''Wave height'' is a term used by mariners, as well as in coastal, ocean and naval engineering.
At sea, the te ...
at various locations in Scotland over a number of years. In 1852, he published a paper in which he suggested that waves increased in height by a ratio approximate to the
square root
In mathematics, a square root of a number is a number such that y^2 = x; in other words, a number whose ''square'' (the result of multiplying the number by itself, or y \cdot y) is . For example, 4 and −4 are square roots of 16 because 4 ...
of their distance from the
windward
In geography and seamanship, windward () and leeward () are directions relative to the wind. Windward is ''upwind'' from the point of reference, i.e., towards the direction from which the wind is coming; leeward is ''downwind'' from the point ...
shore.
Stevenson developed this into the simple formula
, in which
is the wave height in
feet
The foot (: feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is an organ at the terminal part of the leg made up of ...
and
is the
fetch in
miles
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of length; both are based on the older English unit of length equal to 5,280 English f ...
.
Essential components for wave height prediction, most notably
wind speed
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer.
Wind spe ...
, are missing from Stevenson's formula. In 1852, mathematical analysis of the theory of water waves, and methods for numerical assessment of factors such as
shoaling
In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. Ab ...
and
surge
Surge means a sudden transient rush or flood, and may refer to:
Science
* Storm surge, the onshore flow of water associated with a low-pressure weather system
* Surge (glacier), a short-lived event where a glacier can move up to velocities 100 t ...
, were in their infancy. Stevenson's analysis is possibly the first quantitative discussion of wave height as a (square root) function of fetch, and his paper is one of the first quantitative studies of wind speeds in the
planetary boundary layer
In meteorology, the planetary boundary layer (PBL), also known as the atmospheric boundary layer (ABL) or peplosphere, is the lowest part of the atmosphere and its behaviour is directly influenced by its contact with a planetary surface. On Ea ...
.
Modern analysis of Stevenson's formula indicates that it appears to conservatively estimate wave heights for wind speeds up to around 30
miles per hour
Miles per hour (mph, m.p.h., MPH, or mi/h) is a British imperial and United States customary unit of speed expressing the number of miles travelled in one hour. It is used in the United Kingdom, the United States, and a number of smaller count ...
, being based on his observations which most likely were taken for fetch lengths under 100
kilometres
The kilometre ( SI symbol: km; or ), spelt kilometer in American and Philippine English, is a unit of length in the International System of Units (SI), equal to one thousand metres (kilo- being the SI prefix for ). It is the preferred measur ...
, without
fully developed seas. The breakwater at Wick was exposed to a fetch length of approximately 500 kilometres, and wind speeds far in excess of 30 miles per hour, prior to its eventual destruction.
In 1965, the South African engineer
Basil Wrigley Wilson proposed a method which can be used to approximate the significant wave height ''H
1/3'' and period ''T
1/3'' of wind waves generated by a constant wind of speed ''U'' blowing over a fetch length ''F''.
The units for these quantities are as follows:
* ''H
1/3'' in metres (m)
* ''T
1/3'' in seconds (s)
* ''U'' in metres per second (m/s)
* ''F'' in metres (m)
Wilson's formulae apply when the duration of the wind blowing is sufficiently long, as when the wind blows for only a limited time, waves cannot attain the full height and period corresponding to the wind speed and fetch length. Under conditions were the wind blows for a sufficiently long time, for example during a prolonged storm, the wave height and period can be calculated as follows:
:
:
In these formulae, ''g'' denotes the acceleration due to gravity, which is approximately 9.807 m/s
2. The wind speed ''U'' is measured at an elevation of 10 metres above the sea surface. For conditions approximate to those for the Wick breakwater during a storm (fetch length of 500km, wind speed of around 75mph), the graph below shows that Wilson's method predicts a significant wave height (''H
1/3'') of around 1.5 times that of Stevenson's.

Nonetheless, whilst Stevenson's formula is highly limited and unsuitable for engineering design application, it was notable for being an early attempt to apply mathematical theory to hydraulic engineering problems, and shows some limited agreement (albeit within a narrow range) with a more advanced formula developed by
Ramón Iribarren
Ramón Iribarren Cavanilles Doctor of Engineering, Ing.D (15 April 1900 – 21 February 1967) was a Spanish civil engineer and professor of ports at the School of Civil Engineering (, ''ETSICCP'') in Madrid. He was chairman of the Spanish dele ...
in 1942.
A major flaw in Stevenson's formula is the absence of consideration of wind speed, and comparison with Wilson's formula at 3 different wind speeds (30, 50 and 75mph) shows only a reasonable level of agreement for 50mph winds at fetch lengths up to around 100 metres.

Stevenson himself noted that the formula was an
approximation
An approximation is anything that is intentionally similar but not exactly equal to something else.
Etymology and usage
The word ''approximation'' is derived from Latin ''approximatus'', from ''proximus'' meaning ''very near'' and the prefix ...
, and actively encouraged further research into similar problems, imploring young engineers to redouble efforts in the advancement of
coastal engineering
Coastal engineering is a branch of civil engineering concerned with the specific demands posed by constructing at or near the coast, as well as the development of the coast itself.
The fluid dynamics, hydrodynamic impact of especially wind wave, ...
during an 1885 address to the Institution of Civil Engineers in London. In addition to his work on wave growth, he also undertook research into the phenomenon of wave decay inside
harbour
A harbor (American English), or harbour (Commonwealth English; see American and British English spelling differences#-our, -or, spelling differences), is a sheltered body of water where ships, boats, and barges can be Mooring, moored. The t ...
basins.
The breakwater at Wick, Caithness
Stevenson designed and supervised the construction of a
breakwater
Breakwater may refer to:
* Breakwater (structure), a structure for protecting a beach or harbour
Places
* Breakwater, Victoria, a suburb of Geelong, Victoria, Australia
* Breakwater Island, Antarctica
* Breakwater Islands, Nunavut, Canada
* ...
at
Wick
Wick most often refers to:
* Capillary action ("wicking")
** Candle wick, the cord used in a candle or oil lamp
** Solder wick, a copper-braided wire used to desolder electronic contacts
Wick or WICK may also refer to:
Places and placenames ...
in 1863, which at the time was the largest
herring
Herring are various species of forage fish, belonging to the Order (biology), order Clupeiformes.
Herring often move in large Shoaling and schooling, schools around fishing banks and near the coast, found particularly in shallow, temperate wate ...
fishery
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish far ...
in Europe. The inner harbour, designed by
Thomas Telford
Thomas Telford (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotland, as well ...
, was completed in 1811, followed by the construction of the expanded outer harbour by
James Bremner between 1825 and 1834. However, by 1857, the need for increased capacity became evident, leading the British Fishery Society to propose a new breakwater. In 1862 Stevenson, along with his brother David, prepared detailed plans, sections, and specifications for the harbour's extension. This design received support from
Sir John Coode and
John Hawkshaw
Sir John Hawkshaw FRS FRSE FRSA MICE (9 April 1811 – 2 June 1891), was an English civil engineer. He served as President of the Institution of Civil Engineers 1862-63. His most noteworthy work is the Severn Tunnel.
Early life
He was born ...
. A loan of £62,000 was sanctioned by A. M. Rendel, the engineer for the
Public Works Loan Commission.
Construction commenced in April 1863, aiming for a final length of 460 metres. Stevenson's design featured a rubble mound extending to 5.5 metres above the
low water
Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide ...
mark, following the Crane Rocks. This was capped with block walls and in-filled with rubble, providing a
superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships.
Aboard ships and large boats
On water craft, the superstruct ...
up to 16 metres wide. The rubble for the mound was sourced from local quarries and transported by
steam locomotives
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...
. This was then deposited onto the breakwater mound using travelling
gantries that ran along the
staging, marking a possible first in Scotland for this technique.
The seaward wall was constructed with a 6:1 batter. Below the waterline, the blocks were dry-jointed, whereas above the high-water mark, initially
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of Roman civilization
*Epistle to the Romans, shortened to Romans, a letter w ...
and later
Portland cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar (masonry), mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in th ...
mortar was used.
The breakwater failed progressively as a result of several
storms
A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstorm) ...
, and by 1870 it had lost one third of its length. It was eventually abandoned in 1877, after further severe storm damage, despite repeated failed attempts at its reconstruction.
Stevenson noted, in correspondence with the
Institution of Civil Engineers
The Institution of Civil Engineers (ICE) is an independent professional association for civil engineers and a Charitable organization, charitable body in the United Kingdom. Based in London, ICE has over 92,000 members, of whom three-quarters ar ...
, that a single storm had at one stage removed 1,350
tonnes
The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...
of material from the breakwater, but he was unable to provide the height of the waves during the event.
Applying present-day techniques to calculate local wave conditions demonstrates that the breakwater as built would not have survived without mobilising additional restraint, or a mechanism to abate wave forces.
Stevenson's own wave formula would have predicted offshore wave heights for Wick of around 8 to 10
metres
The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of ...
, whereas modern observations show that the
North Sea
The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...
exhibits wave heights of up to two to three times this figure.
Family
He was brother of the lighthouse engineers
Alan
Alan may refer to:
People
*Alan (surname), an English and Kurdish surname
* Alan (given name), an English given name
** List of people with given name Alan
''Following are people commonly referred to solely by "Alan" or by a homonymous name.''
* ...
and
David Stevenson, between 1854 and 1886 he designed many lighthouses, with his brother David, and then with David's son
David Alan Stevenson
David Alan Stevenson (21 July 1854 in Edinburgh – 11 April 1938) was a lighthouse engineer who built 26 lighthouses in and around Scotland.
Life
He was born on 21 July 1854 the son of David Stevenson and his wife, Elizabeth Mackay. His e ...
.
He married Margaret Isabella "Maggie" Balfour in 1848, daughter of Rev Lewis Balfour. Their son was the writer
Robert Louis Stevenson
Robert Louis Stevenson (born Robert Lewis Balfour Stevenson; 13 November 1850 – 3 December 1894) was a Scottish novelist, essayist, poet and travel writer. He is best known for works such as ''Treasure Island'', ''Strange Case of Dr Jekyll ...
, who initially caused him much disappointment by failing to follow the engineering interests of his family.
His wife's younger brother,
James Melville Balfour (i.e. his brother-in-law), trained under D. & T. Stevenson and then emigrated to New Zealand, where he was first the marine engineer for
Otago Province
The Otago Province was a province of New Zealand until the abolition of provincial government in 1876.
The capital of the province was Dunedin. Southland Province split from Otago in 1861, but became part of the province again in 1870.
Area a ...
before he was appointed Colonial Marine Engineer.
Lighthouses designed by Thomas Stevenson
Gallery
File:Townhouse at 17 Heriot Row, Edinburgh.jpg, upTownhouse at 17 Heriot Row, Edinburgh
File:Condensing light. Lighthouse optic, designed by Thomas Stevenson. Chance Brothers and Company, Birmingham, 1866. National Museum of Scotland, Edinburgh.jpg, Condensing light. Lighthouse optic, designed by Thomas Stevenson. Chance Brothers and Company, Birmingham, 1866. National Museum of Scotland, Edinburgh
File:Thomas Srevenson by Sir George Reid 1878 SNPG.jpg, upThomas Stevenson by Sir George Reid, 1878
See also
*
Richard Henry Brunton, "father of Japanese lighthouses"
*
John Richardson Wigham, Irish inventor and lighthouse engineer
References
External links
Eilean Bàn – Kyleakin Lighthouse'Lighthouse Library' of the Northern Lighthouse Board
{{DEFAULTSORT:Stevenson, Thomas
1818 births
1887 deaths
Lighthouse builders
Presidents of the Royal Society of Edinburgh
People educated at the Royal High School, Edinburgh
Alumni of the University of Edinburgh
Scottish civil engineers
Scottish inventors
Burials at the New Calton Burial Ground
Scottish meteorologists
19th-century Scottish antiquarians
Engineers from Edinburgh
Stevenson family (Scotland)
Fellows_of_the_Society_of_Antiquaries_of_Scotland