Question: Huber Manufacturing Co. created what sort of self-propelled steam engine?

Context articles: Cooper Manufacturing Co. v. Ferguson
Watt steam engine
Traction engine
Huber Manufacturing Co.
Edward Pritchard (engineer)
Model steam engine
History of the steam engine
James P. Allaire
Steam power during the Industrial Revolution
Emily (Thomas &amp; Friends)

Cooper Manufacturing Co. v. Ferguson, 113 U.S. 727 (1885) , was a suit regarding the legitimacy of a sale of a steam engine and other machinery in the State of Ohio.
The Watt steam engine (alternatively known as the Boulton and Watt steam engine) was the first type of steam engine to make use of a separate condenser.
 It was a vacuum or "atmospheric" engine using steam at a pressure just above atmospheric to create a partial vacuum beneath the piston.
 The difference between atmospheric pressure above the piston and the partial vacuum below drove the piston down the cylinder.
 James Watt avoided the use of high pressure steam because of safety concerns.
 Watt's design became synonymous with steam engines, due in no small part to his business partner, Matthew Boulton.
A traction engine is a self-propelled steam engine used to move heavy loads on roads, plough ground or to provide power at a chosen location.
 The name derives from the Latin "tractus", meaning 'drawn', since the prime function of any traction engine is to draw a load behind it.
 They are sometimes called road locomotives to distinguish them from railway locomotives – that is, steam engines that run on rails.
The New Huber Traction engine company of Marion, Ohio, built engines from 1885 to 1903.
 In several respects the engines were different from their competitors in that the boilers had return tubes, (a two pass system, much like a marine boiler) and engines were reversed on top of the boiler (contrary to conventional practice with engine forward and crank at rear).
 The boilers were economical as they captured more heat from the stack gases.
Edward "Ted" Pritchard (28 August 1930 – 16 August 2007) was an Australian mechanical engineer, inventor and developer of small scale modern steam engines. Pritchard was obsessed by the virtues of modern steam as compared to the internal combustion engine.
 He believed that for a fraction of the investment in the development of internal combustion engines, modern small-scale steam, externally fired engines, could prove to be of far greater efficiency and utility, exhibit better combustion characteristics, have lower emissions, greater fuel efficiency, higher torque and better power-to-weight ratios.
 His commitment saw him nearly single-handedly attempt to launch a steam driven car industry in Australia in the 1970s, an effort that ultimately sent him bankrupt.
 Towards the end of his life he continued to refine the engineering principles and designs of his engines and he left a design for what he referred to as “the best small steam engine the world has ever seen”.
 Pritchard claimed that he had, “done for the steam engine what IBM did for the computer, made it small and personal”.
A model steam engine is a small steam engine built as an educational toy for children (in which case it is also called a toy steam engine) or for adult live steam enthusiasts.
 Between the 18th and early 20th centuries, demonstration models were also in use at universities and engineering schools, frequently designed and built by students as part of their curriculum.
The first recorded rudimentary steam engine was the aeolipile described by Heron of Alexandria in 1st-century Roman Egypt.
 Several steam-powered devices were later experimented with or proposed, such as Taqi al-Din's steam jack, a steam turbine in 16th-century Ottoman Egypt, and Thomas Savery's steam pump in 17th-century England.
 In 1712, Thomas Newcomen's atmospheric engine became the first commercially successful engine using the principle of the piston and cylinder, which was the fundamental type steam engine used until the early 20th century.
 The steam engine was used to pump water out of coal mines
James Peter Allaire (July 12, 1785 – May 20, 1858) was a noted master mechanic and steam engine builder, and founder of the Allaire Iron Works (est. 1815), the first marine steam engine company in New York City, and later Howell Works (est. 1822), in Wall Township, New Jersey.
 His credits also include building both the first compound steam engine for marine use and the first New York City tenement structure.
The steam engine was one of the most important technologies of the Industrial Revolution, although steam did not replace water power in importance in Britain until after the Industrial Revolution.
 From Englishman Thomas Newcomen's atmospheric engine, of 1712, through major developments by Scottish inventor and mechanical engineer James Watt, the steam engine began to be used in many industrial settings, not just in mining, where the first engines had been used to pump water from deep workings.
 Early mills had run successfully with water power, but by using a steam engine a factory could be located anywhere, not just close to water.
 Water power varied with the seasons and was not available at times due to freezing, floods and dry spells.
Emily the Stirling Engine is a fictional steam locomotive from the television series "Thomas & Friends".
 She was the second female steam engine (Lady was the first female steam engine) and first female steam engine to be featured in the television series (Daisy was the first female Diesel engine and female engine), and became a member of the "Steam Team", as the eight core characters of the series which she became in "Calling All Engines!
", and appeared in lots of episodes more often.
 She is also the only female in the Steam Team.
 She is painted dark green and has two large driving wheels and a shiny brass safety valve cover.