Inventors of unconventional forms of power

Clark, [Josiah] Latimer
Born Great Marlow, Buckinghamshire, on 10 March 1822. Died 30 October 1898 in London. Buried in Hanwell cemetery, Ealing. Latimer Clark began his working life as a chemist, working with a chemical manufacturer in Dublin; but in 1847 he commenced railway surveying, and in 1848 was appointed assistant engineer under his brother Edwin to the Menai Strait Bridge. He helped his brother in preparing his book on that bridge and contributed to it an account of the tides in the Menai Strait.
In August 1850 he became assistant engineer under his brother to the Electric and International Telegraph Company. A series of his researches made in 1853 on telegraph wires formed part of the government report on submarine telegraph cables. Some ten years later he succeeded his brother as chief engineer to the company, and held this post until the various telegraphic systems were nationalized in 1870. Clark introduced several improvements in the telegraph system, notably by coating the gutta-percha enclosing underground wires with a solution which prevented its decay; he also invented a very effective insulator to carry telegraph wires. He filed 150 patents, in different countries, for these inventions. In 1853 he proved that high and low tension currents travelled at the same rate irrespective of pressure; his experiments were repeated before Faraday and delivered at the Royal Institution in 1854. In 1855 Clark published his results in a pamphlet, Experimental investigation of the laws which govern the propagation of the electric current in submarine telegraph cables.
In 1861 Clark entered into partnership with Sir Charles Tilston Bright, and their joint paper read at the Manchester meeting of the British Association in that year led to the appointment of the committee which defined standards for measuring the nature and strength of electrical currents. With Bright he invented in 1862 the method of covering submarine cables with asphalt, hemp, and silica to extend their life (Bright and Clark's compound), and for eight years the firm was engaged in laying telegraph cables, principally in the East. On 25 September 1868 Bright and Clark dissolved the partnership, and Clark formed with Henry Charles Forde (1827–1897) the contracting firm Clark, Forde, and Taylor, of Great Winchester Street, London. Under Clark's supervision some 50,000 miles of submarine cable were laid across the world's oceans, linking capital cities and commercial ports.
Clark was also interested in other forms of engineering. His earliest patent (1854) had been one for ‘conveying letters or parcels between places by the pressure of air and vacuum’. The Pneumatic Despatch Company was established in 1857 with Clark as its engineer. He constructed the 4 foot 6 inch pneumatic tube between the General Post Office (GPO) and Euston Station, but the system was not profitable, and after two years it was handed over to the GPO. In 1874 he entered into partnership with John Standfield as hydraulic and canal engineers; the works of the firm were at Grays, Essex, and it constructed numerous floating docks, notably those at Vladivostok, Hamburg, Havana, Stettin, and North Shields. He was also senior partner in the firm of Latimer Clark, Muirhead & Co., formed in 1875 to manufacture electrical apparatus and machinery.
In 1870–71 Clark took a large part in founding the Society of Telegraph Engineers and Electricians (later renamed the Institution of Electrical Engineers), and in 1874–5 he served as its fourth president. On 6 June 1889 he was elected FRS, and he was also fellow of the Royal Astronomical and Geographical societies. He devoted much of his leisure to astronomy and photography; in 1853 he invented a camera for taking stereoscopic pictures with a single lens, and in 1857 he assisted Sir George Biddell Airy to devise a method of indicating Greenwich mean time throughout the country. J.T. Humphreys described him as a genial man with pleasant manners and a large fund of information and a good memory, all of which combined to make him a popular figure.
ODNB entry by A.F. Pollard, revised by Anita McConnell; also  Hadfield's Atmospheric railways.. Portrayed in Conference of Engineers at Britannia Bridge by John Lucas (see Marshall for key to those in picture).

Clegg, Samuel
Born in Manchester in 1782. Received a scientific training from Dalton and was apprenticed at Boulton & Watt. On 3 January 1838 in association with the Samudas patented (No. 7920) a leather valve designed to seal an iron tube with the assistance of tallow which acted as the key element in the atmospheric railway.

Hallette (or Halette), Alexis
Alexis Hallette (1788-1846) settled in Arras in 1812. In 1829, two locomotives were built by Robert Stephenson in Newcastle for France: one went to the brothers Seguin in Lyon, the other to Alexis Hallette. Initially Hallette produced spare parts, but later began locomotive manufacture. Hallette became involved in atmospheric railways using rubber rather than leather as the sealing system (rubber is a far more suitable material). Experimental systems were set up both in the Arras factory and at Peckham in England. In 1847 a section of railway near Saint Germain on a steep gradient was fitted with the system: vulcanized rubber buffers were fitted to the vehicles for emergency use. Hallette died on 3 July 1846. Hadfield's Atmospheric railways. plus French material off Internet. Hadfield appeared to be unaware of Hallette's Christian name and is entererd in the indexx as "Hallette, M."!.

Medhurst, George
Baptized on 11 February 1759 at Shoreham, Kent. He began as a clockmaker in Clerkenwell until the imposition in 1797 of a duty on clocks depressed trade. He then turned to engineering, working at Battle Bridge, Clerkenwell. His first patent, filed in 1799 (No. 2299) was for a windmill and pump for compressing air to obtain motive power. The sails of the windmill were arranged in the manner which became commonplace for pumping windmills, while his machinery showed great ingenuity, with a governor attached to vary the length of stroke to the pump, according to the wind strength and the pressure of air in the reservoir. The specification included a description of a small rotary engine to be worked by compressed air. Medhurst pursued the idea of taking advantage of the available wind to compress large bodies of air, as an energy source for use when required, throughout his life.
The following year Medhurst patented his Aeolian engine (No. 2431/1800), by which a carriage could be propelled by compressed air contained in a reservoir beneath the vehicle. In an undated pamphlet he proposed the establishment of regular coach services, with pumping stations along the route, to replenish the reservoirs. He also described an engine worked by gas produced by exploding small quantities of gunpowder at regular intervals in the cylinder. In 1801 he patented a compound crank for converting rotary into rectilinear motion (No. 2467/1801).
By about 1800 Medhurst had established himself in Westminster as a maker of scales and weighing machines, machinist, and ironfounder. He was the inventor of the equal balance weighing machine, patented in 1817 (No. 4164), which found a place on the counter of most retail shops, and he also made heavy duty platforms for weighing goods in sacks, cases, or carts, and for weighing jockeys.
Medhurst was the first to suggest pneumatic dispatch, as it was later called, whereby letters and small packages were propelled along a tube by compressed air. This idea was not patented; Medhurst published a description in 1810, followed in 1812 by proposals for a pneumatic passenger railway. His plan specified brick tunnels of 30 feet cross-section, through which closely fitting passenger or goods carriages ran on rails. The carriages might, he thought, reach a speed of 50 miile/h, with goods conveyed at the low cost of a penny per ton per mile, passengers at a farthing per mile. Recognizing that people might not be willing to be propelled through a tube, Medhurst also proposed carriages running on rails on the roadway, connected to a piston driven through a continuous tube beneath the rails. He did not put these plans into action. Like others with similar ideas at this time, he could not devise a practical method of sealing the longitudinal slit in the pressurized tube while permitting the tow bar to pass along.
Medhurst's steam carriage met with more success; carrying one man it ran between Paddington and Islington on 3 April 1820 and again on 6 July. A year later his more substantial carriage ran up and down Paddington Hill at 5 mile/h.. By 1827 Medhurst was offering to sell a carriage able to carry four persons at 7 mile/h.. At this time he was also advertising his patent canal lock, to prevent loss of water, and a leak proof lock gate, though no patents were filed under his name. Medhurst died early in September 1827 and was buried at the church of St Peter and St Paul, Shoreham, on 10 September. From ODNB entry by R.B. Prosser, revised Anita McConnell. Also included in Hadfield's Atmospheric railways.

Pinkus, Henry
An American living in London: in 1835 issued a prospectus for the National Pneumatic Railway Association.. Instigated several experiments for pneumatic traction on roads, railways and canals, and even for ploughing where a rubber hose (NB pre-vulcanization) was suggested. Hadfield's Atmospheric railways..

Rammell, T.W.
In 1857 he published A new plan for street railways which led in 1859 to the Pneumatic Despatch Company. This in turn led to an underground tube from Euston station to the Post Office North Western District Post Office in Eversholt Street. This was later extended to Holborn. Hadfield's Atmospheric railways...

Samuda, Joseph d'Aguilar
R.B. Wilson notes that Samuda (1813-1885) was the patentee with Samuel Clegg of the atmospheric system of traction. ODNB entry by G.C. Boase revised by Anita McConnell: born into Portuguese Jewish family on 21 May 1813 in London, and died in London on 27 April 1885. Work of Joseph and his brother Jacob dominates Hadfield's Atmospheric railways..