Macneill's Road Indicator was a

dynamometer A dynamometer or "dyno" for short, is a device for simultaneously measuring the torque and rotational speed ( RPM) of an engine, motor or other rotating prime mover so that its instantaneous power may be calculated, and usually displayed by t ...

for ascertaining the force necessary to draw a carriage over different kind of roads and pavements. It was developed by

John Benjamin Macneill Sir John Benjamin Macneill FRS (1793 – 2 March 1880) was an eminent Irish civil engineer of the 19th century, closely associated with Thomas Telford. His most notable projects were railway schemes in Ireland. Life He was born in Mountpleasant ...

in the late 1820s.

Prototype

Macneill's road indicator was completed according to drawings laid before and authorised by the Parliamentary

Commissioners A commissioner (commonly abbreviated as Comm'r) is, in principle, a member of a commission or an individual who has been given a commission (official charge or authority to do something). In practice, the title of commissioner has evolved to in ...

in 1829. It was first used on the road between London and Shrewsbury. A description of and the method of using it was included the Sevent report of the

(1830).

Improved version

Macneill made further improvement in the road indicator enable it to measure bearing, inclination, time and distance travelled. In April 1833 it was used in experiments with an iron boat on the

Paddington Canal The Grand Junction Canal is a canal in England from Braunston in Northamptonshire to the River Thames at Brentford, with a number of branches. The mainline was built between 1793 and 1805, to improve the route from the Midlands to London, by-p ...

for the purpose of ascertaining the law of

resistance Resistance may refer to: Arts, entertainment, and media Comics * Either of two similarly named but otherwise unrelated comic book series, both published by Wildstorm: ** ''Resistance'' (comics), based on the video game of the same title ** ''T ...

, or force of

traction Traction may refer to: Engineering *Forces: ** Traction (engineering), adhesive friction or force ** Traction vector, in mechanics, the force per unit area on a surface, including normal and shear components * Traction motor, an electric motor ...

, at different degrees of

velocity Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity i ...

. It was demonstrated in

Regent's Park Regent's Park (officially The Regent's Park) is one of the Royal Parks of London. It occupies of high ground in north-west Inner London, administratively split between the City of Westminster and the Borough of Camden (and historically betwee ...

in presence of

Charles Gordon-Lennox, 5th Duke of Richmond Charles Gordon-Lennox, 5th Duke of Richmond, (3 August 179121 October 1860), of Goodwood House near Chichester in West Sussex, was a British peer, soldier and prominent Conservative politician. Origins He was born "Charles Lennox", the son an ...

and Sir

Henry Parnell Henry Brooke Parnell, 1st Baron Congleton PC (3 July 1776 – 8 June 1842), known as Sir Henry Parnell, Bt, from 1812 to 1841, was an Irish writer and Whig politician. He was a member of the Whig administrations headed by Lord Grey and Lord M ...

18 May 1833, and two days after reported to the select committee of the House of Lords appointed to examine the

turnpike Turnpike often refers to: * A type of gate, another word for a turnstile * In the United States, a toll road Turnpike may also refer to: Roads United Kingdom * A turnpike road, a principal road maintained by a turnpike trust, a body with powers ...

returns with description and measured data for the period 1829 - 1832. The experiments showed that the force of

was nearly in an exact proportion to the hardness of the road. In 1835 Macneill gave evidence to the House of Common on the relative advantages of the telegraph, elliptical and other springs as regards the draught of carriages.House of Commons Paper, Vol 42, 1840
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References

Dynamometers