![John Loudon McAdam, 1830, National Gallery, London](https://upload.wikimedia.org/wikipedia/commons/6/68/John_Loudon_McAdam%2C_1830%2C_National_Gallery%2C_London.JPG)
John Loudon McAdam (23 September 1756
– 26 November 1836) was a
Scottish civil engineer and road-builder. He invented a new process, "
macadam
Macadam is a type of road construction, pioneered by Scottish engineer John Loudon McAdam around 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly. A binding layer of stone dust (crushed stone from the o ...
isation", for building roads with a smooth hard surface, using controlled materials of mixed particle size and predetermined structure, that would be more durable and less muddy than
soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
-based tracks.
Modern road construction still reflects McAdam's influence. Of subsequent improvements, the most significant was the introduction of
tar
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bit ...
(originally
coal tar
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasi ...
) to bind the road surface's stones together, "
tarmac Tarmac may refer to:
Engineered surfaces
* Tarmacadam, a mainly historical tar-based material for macadamising road surfaces, patented in 1902
* Asphalt concrete, a macadamising material using asphalt instead of tar which has largely superseded ta ...
" (for Tar Macadam.)
Early life
McAdam was born in
Ayr
Ayr (; sco, Ayr; gd, Inbhir Àir, "Mouth of the River Ayr") is a town situated on the southwest coast of Scotland. It is the administrative centre of the South Ayrshire Subdivisions of Scotland, council area and the historic Shires of Scotlan ...
, Scotland.
He was the youngest of ten children and second son of the Baron of Waterhead. He moved to Lagwine at
Carsphairn
Carsphairn ( gd, An Còrsa Feàrna) is a village in the historic county of Kirkcudbrightshire in Dumfries and Galloway, Scotland. It is located about halfway between Dalmellington and St John's Town of Dalry, on the A713 road. Carsphairn annua ...
when still a child to live with his grandparents. The family name was traditionally McGregor, but was changed to McAdam (claiming descent from the Biblical
Adam
Adam; el, Ἀδάμ, Adám; la, Adam is the name given in Genesis 1-5 to the first human. Beyond its use as the name of the first man, ''adam'' is also used in the Bible as a pronoun, individually as "a human" and in a collective sense as " ...
) for political reasons in
James VI
James is a common English language surname and given name:
*James (name), the typically masculine first name James
* James (surname), various people with the last name James
James or James City may also refer to:
People
* King James (disambiguat ...
's reign.
He moved to
New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
in 1770 and, as a
merchant
A merchant is a person who trades in commodities produced by other people, especially one who trades with foreign countries. Historically, a merchant is anyone who is involved in business or trade. Merchants have operated for as long as indust ...
and
prize agent during the
American Revolution
The American Revolution was an ideological and political revolution that occurred in British America between 1765 and 1791. The Americans in the Thirteen Colonies formed independent states that defeated the British in the American Revolut ...
, made his fortune working at his uncle
William McAdam's
counting house
A counting house, or counting room, was traditionally an office in which the financial books of a business were kept. It was also the place that the business received appointments and correspondence relating to demands for payment.
As the use of ...
.
He returned to Scotland in 1783 and purchased an
estate at Sauchrie,
Ayrshire
Ayrshire ( gd, Siorrachd Inbhir Àir, ) is a historic county and registration county in south-west Scotland, located on the shores of the Firth of Clyde. Its principal towns include Ayr, Kilmarnock and Irvine and it borders the counties of Re ...
.
Besides taking part in local Ayrshire affairs, McAdam operated the Kaims Colliery. The colliery supplied coal to the British Tar Company, of
Archibald Cochrane, 9th Earl of Dundonald
Archibald Cochrane, 9th Earl of Dundonald FRSE (1 January 1748 – 1 July 1831) was a Scottish nobleman and inventor.
Life
The son of Thomas Cochrane, 8th Earl of Dundonald, he joined the British Army as a youth and also served time in the Roya ...
, and partners in the
coal tar
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasi ...
trade; McAdam ran its
kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
s. He further was involved in the ironworks at
Muirkirk
Muirkirk ( gd, Eaglais an t-Slèibh) is a small village in East Ayrshire, southwest Scotland. It is located on the north bank of the River Ayr, between Cumnock and Glenbuck on the A70.
Conservation
The Muirkirk & North Lowther Uplands Special ...
, which was a customer for the coke byproduct of the tar business. This business connection is the only direct relationship of McAdam and tar.
Career
![John Loudoun McAdam's Gravestone, Moffat](https://upload.wikimedia.org/wikipedia/commons/b/ba/John_Loudoun_McAdam%27s_Gravestone%2C_Moffat.JPG)
McAdam became a trustee of the Ayrshire Turnpike in 1783 and became increasingly involved with day-to-day road construction over the next 10 years. In 1802 he moved to
Bristol
Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
, England and he became general surveyor for the Bristol Corporation in 1804. He put forward his ideas in evidence to
Parliamentary
A parliamentary system, or parliamentarian democracy, is a system of democracy, democratic government, governance of a sovereign state, state (or subordinate entity) where the Executive (government), executive derives its democratic legitimacy ...
enquiries in 1810, 1819 and 1823.
In two
treatise
A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject and its conclusions."Treat ...
s written in 1816 and 1819 (''Remarks on the Present System of Road-Making'' and ''Practical Essay on the Scientific Repair and Preservation of Roads'') he argued that roads needed to be raised above the surrounding ground and constructed from layered rocks and gravel in a systematic manner.
![City roads and pavements (1902) page 16 macadam road](https://upload.wikimedia.org/wikipedia/commons/1/14/City_roads_and_pavements_%281902%29_page_16_macadam_road.png)
McAdam had also been appointed
surveyor
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ca ...
to the Bristol
Turnpike Trust
Turnpike trusts were bodies set up by individual Acts of Parliament in the United Kingdom, acts of Parliament, with powers to collect road toll road, tolls for maintaining the principal roads in Kingdom of Great Britain, Britain from the 17th b ...
in 1816, where he decided to remake the roads under his care with crushed
stone
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...
bound with gravel on a firm base of large stones. A
camber
Camber may refer to a variety of curvatures and angles:
* Camber angle, the angle made by the wheels of a vehicle
* Camber beam, an upward curvature of a joist to compensate for load deflection due in buildings
* Camber thrust in bike technology
* ...
, making the road slightly convex, ensured rainwater rapidly drained off the road rather than penetrate and damage the road's foundations. This construction method, the greatest advance in road construction since
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 ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a letter ...
times, became known as "macadamisation", or, more simply, "
macadam
Macadam is a type of road construction, pioneered by Scottish engineer John Loudon McAdam around 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly. A binding layer of stone dust (crushed stone from the o ...
".
The macadam method spread very quickly across the world. The first macadam road in North America, the
National Road
The National Road (also known as the Cumberland Road) was the first major improved highway in the United States built by the Federal Government of the United States, federal government. Built between 1811 and 1837, the road connected the Pot ...
, was completed in the 1830s and most of the main roads in Europe were subject to the McAdam process by the end of the nineteenth century.
Although McAdam was paid
£5,000 for his Bristol Turnpike Trust work and made "Surveyor-General of Metropolitan Roads" in 1820, professional jealousy cut a £5,000 grant for expenses from the
Parliament of the United Kingdom
The Parliament of the United Kingdom is the supreme legislative body of the United Kingdom, the Crown Dependencies and the British Overseas Territories. It meets at the Palace of Westminster, London. It alone possesses legislative suprema ...
to £2,000 in 1827.
His efficient road-building and management work had revealed the corruption and abuse of
road tolls by unscrupulous turnpike trusts, many of which were run at a deliberate loss despite high toll receipts.
Death and descendants
McAdam died in
Moffat
Moffat ( gd, Mofad) is a burgh and parish in Dumfriesshire, now part of the Dumfries and Galloway local authority area in Scotland. It lies on the River Annan, with a population of around 2,500. It was a centre of the wool trade and a spa town.
...
,
Dumfriesshire
Dumfriesshire or the County of Dumfries or Shire of Dumfries (''Siorrachd Dhùn Phris'' in Gaelic) is a historic county and registration county in southern Scotland. The Dumfries lieutenancy area covers a similar area to the historic county.
I ...
, while returning to his home in
Hoddesdon
Hoddesdon () is a town in the Borough of Broxbourne, Hertfordshire, lying entirely within the London Metropolitan Area and Greater London Urban Area. The area is on the River Lea and the Lee Navigation along with the New River.
Hoddesdon is ...
, Hertfordshire, from his annual summer visit to Scotland. His three sons, and in turn four grandsons, followed him into the profession and assisted with the management of
turnpike trust
Turnpike trusts were bodies set up by individual Acts of Parliament in the United Kingdom, acts of Parliament, with powers to collect road toll road, tolls for maintaining the principal roads in Kingdom of Great Britain, Britain from the 17th b ...
s around the country. His second surviving son, James Nicoll McAdam, the "Colossus of Roads", was
knighted
A knight is a person granted an honorary title of knighthood by a head of state (including the Pope) or representative for service to the monarch, the Christian denomination, church or the country, especially in a military capacity. Knighthood ...
for managing turnpike trusts: a knighthood, it is said, previously offered to his father but declined.
References
* Devereux, Roy (1936). ''John Loudon McAdam: Chapters in the History of Highways''. London: Oxford University Press.
External links
*
*
*
Remarks on the Present System of Road Makingby John Loudon McAdam, 1821, from
Google Book Search
Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google Inc. that searches the full text of books and magazines that Google has scanned, converted to text using optical c ...
Magazine from the Department of Public Works in Puerto Rico indicating, with a map, about a firm called McAdams that built many highways in Puerto Rico
{{DEFAULTSORT:McAdam, John Loudon
1756 births
1836 deaths
People from Hoddesdon
People from Maybole
People from South Ayrshire
People of the Industrial Revolution
Scottish civil engineers
Scottish engineers
Scottish inventors
Scottish non-fiction writers