George Medhurst
Encyclopedia
George Medhurst was a mechanical engineer and inventor, who pioneered the use of compressed air
as a means of propulsion. His ideas led directly to the development of the first atmospheric railway
.
He was born in Shoreham, Kent
and trained as a clockmaker at Clerkenwell
, London
, but later became interested in pneumatics
.
In 1799 he filed a patent for a wind pump for compressing air to obtain motive power and the following year he patented his ‘Aeolian’ engine which used compressed air to power vehicles. In his pamphlet On the properties, power, & application of the Aeolian engine, with a plan and particulars for carrying it into execution, Medhurst proposed the establishment of Aeolian coach services, operated by pumping stations along the route.
In 1810 he published A new method of conveying letters and goods with great certainty and rapidity by air, but did not patent the idea. This was followed in 1812 by his Calculations and remarks tending to prove the practicability, effects and advantages of a plan for the rapid conveyance of goods and passengers upon an iron road through a tube of 30 feet in area by the power and velocity of air. He also envisioned carriages running on rails, propelled by a continuous tube beneath the rails, as would later happened in the atmospheric railway
. Neither of these ideas was put into practical operation at the time. Shortly before his death in September 1827 Medhurst returned to the idea of pneumatic propulsion with his publication of A New System of Inland Conveyance, for Goods and Passengers ... with the velocity of sixty miles in an hour ... without the aid of horses or any animal power. [With plates.]
Other, more successful, inventions by Medhurst included a steam carriage, a ‘leak proof’ canal lock gate and a variety of weighing and balancing machines.
p.240.
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
as a means of propulsion. His ideas led directly to the development of the first atmospheric railway
Atmospheric railway
An atmospheric railway uses air pressure to provide power for propulsion. In one plan a pneumatic tube is laid between the rails, with a piston running in it suspended from the train through a sealable slot in the top of the tube. Alternatively, the whole tunnel may be the pneumatic tube with the...
.
He was born in Shoreham, Kent
Shoreham, Kent
Shoreham is a village and civil parish in the valley of the River Darent six miles north of Sevenoaks in Kent: it is in the District of Sevenoaks. The parish includes the settlements of Badgers Mount and Well Hill....
and trained as a clockmaker at Clerkenwell
Clerkenwell
Clerkenwell is an area of central London in the London Borough of Islington. From 1900 to 1965 it was part of the Metropolitan Borough of Finsbury. The well after which it was named was rediscovered in 1924. The watchmaking and watch repairing trades were once of great importance...
, London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, but later became interested in pneumatics
Pneumatics
Pneumatics is a branch of technology, which deals with the study and application of use of pressurized gas to effect mechanical motion.Pneumatic systems are extensively used in industry, where factories are commonly plumbed with compressed air or compressed inert gases...
.
In 1799 he filed a patent for a wind pump for compressing air to obtain motive power and the following year he patented his ‘Aeolian’ engine which used compressed air to power vehicles. In his pamphlet On the properties, power, & application of the Aeolian engine, with a plan and particulars for carrying it into execution, Medhurst proposed the establishment of Aeolian coach services, operated by pumping stations along the route.
In 1810 he published A new method of conveying letters and goods with great certainty and rapidity by air, but did not patent the idea. This was followed in 1812 by his Calculations and remarks tending to prove the practicability, effects and advantages of a plan for the rapid conveyance of goods and passengers upon an iron road through a tube of 30 feet in area by the power and velocity of air. He also envisioned carriages running on rails, propelled by a continuous tube beneath the rails, as would later happened in the atmospheric railway
Atmospheric railway
An atmospheric railway uses air pressure to provide power for propulsion. In one plan a pneumatic tube is laid between the rails, with a piston running in it suspended from the train through a sealable slot in the top of the tube. Alternatively, the whole tunnel may be the pneumatic tube with the...
. Neither of these ideas was put into practical operation at the time. Shortly before his death in September 1827 Medhurst returned to the idea of pneumatic propulsion with his publication of A New System of Inland Conveyance, for Goods and Passengers ... with the velocity of sixty miles in an hour ... without the aid of horses or any animal power. [With plates.]
Other, more successful, inventions by Medhurst included a steam carriage, a ‘leak proof’ canal lock gate and a variety of weighing and balancing machines.
Sources
R. B. Prosser, ‘Medhurst, George (bap. 1759, d. 1827)’, rev. Anita McConnell, Oxford Dictionary of National Biography, Oxford University Press, 2004; online edn, Jan 2008 accessed 9 Jan 2009.p.240.