Question:  John Fowler & Co produced a tracked version of a brand of what?

Context paragraphs:
John Fowler &amp; Co.: John Fowler & Co Engineers of Leathley Road, Hunslet, Leeds, West Yorkshire, England produced traction engines and ploughing implements and equipment, as well as railway equipment.  Fowler also produced the Track Marshall tractor which was a tracked version of the Field Marshall.  British Railways Engineering Department locomotives ED1 to ED7 were built by Fowler

John Fowler Trow: John Fowler Trow (1810-1886) was a printer and publisher in New York City.  Born in Andover, Massachusetts, he moved to New York in 1833.  He began publishing city directories in 1848.  His business eventually became "John F. Trow & Son," and then "John F. Trow & Co." Employees included Peter C. Baker.  After Trow's death in 1886, "Trow's Directory" continued annually for some years.

Maurie Fowler: Maurice John Fowler (born 10 August 1944, in Geelong) was a former Australian rules footballer, after making the senior list of the Carlton Football Club for 5 years and finally moving to Melbourne from Kyabram (where he played 120 games) in 1966 and played 8 senior games.

Field Marshall: Field-Marshall is a brand of farm tractor which was manufactured by Marshall, Sons & Co. of Gainsborough, Lincolnshire in the United Kingdom.

John Fowler (politician): John Fowler (April 27, 1756 – August 22, 1840), sometimes referred to as Captain John Fowler, was a planter and early American political leader in Virginia and later Kentucky.  He was a Jeffersonian Democrat who served as a Democratic-Republican member of the United States House of Representatives from Kentucky in the United States Congress from 1797 to 1807.  Fowler was also an early settler of and civic leader in Lexington, Kentucky.

Fowler's Ghost: "Fowler's Ghost" is the nickname given to an experimental fireless 2-4-0 steam locomotive designed by John Fowler and built in 1861 for use on the Metropolitan Railway, London's first underground railway.  The broad gauge locomotive used exhaust recondensing techniques and a large quantity of fire bricks to retain heat and prevent the emission of smoke and steam in tunnels.

The Voodoo Jets: The Voodoo Jets are a power trio from Southern Connecticut who play power pop/rock music without electric guitars.  The instrument line-up includes keyboards, bass guitar, and drums.  The band was formed in 2000 and their 2006 album, "Supersonic" (produced by David Minehan), was released on 3 Nutz Music and features 12 songs.  Their second album, "From Greens to Eternity" (featuring 13 tracks), was released in 2010 after the passing of band member John Fowler.

John Fowler (agricultural engineer): Fowler was born in Melksham, Wiltshire.  His father, John Fowler senior was a wealthy Quaker merchant, who had married Rebecca Hull, and together they had three daughters and five sons, of whom Fowler was the third son.  When he left school Fowler followed his father’s wishes and began working for a local corn merchant, but when he came of age in 1847 he turned his back on the corn business and joined the engineering firm of Gilkes Wilson and Company of Middlesbrough.  Amongst other things, the company was involved in building steam locomotives and colliery winding engines.  The company built a number of locomotives for the Stockton and Darlington Railway.

Sir John Fowler, 1st Baronet: Sir John Fowler, 1st Baronet, KCMG, LLD, FRSE (15 July 1817 – 20 November 1898) was an English civil engineer specialising in the construction of railways and railway infrastructure.  In the 1850s and 1860s, he was engineer for the world's first underground railway, London's Metropolitan Railway, built by the "cut-and-cover" method under city streets.  In the 1880s, he was chief engineer for the Forth Railway Bridge, which opened in 1890.  Fowler's was a long and eminent career, spanning most of the 19th century's railway expansion, and he was engineer, adviser or consultant to many British and foreign railway companies and governments.  He was the youngest president of the Institution of Civil Engineers, between 1865 and 1867, and his major works represent a lasting legacy of Victorian engineering.

Clarkboro Ferry: The Clarkboro Ferry is a cable ferry in the Canadian province of Saskatchewan.  The ferry crosses the South Saskatchewan River at Clark's Crossing, carrying Grid Road 784 across the river, and connecting Warman in the west and Aberdeen in the east.  The ferry is named for the community of Clarkboro located southeast of the ferry's eastern terminal.  The former town of Clarkboro was home to a section crew on the CNR, had a post office, a general store, a railroad siding, a water tower for steam locomotives and two grain elevators (Saskatchewan Pool Elevator Co.  No. 760).  Both Clarkboro and Clark's Crossing are named for John Fowler Clark, who homesteaded the area in 1882.

Supporting paragraphs: John Fowler &amp; Co. Field Marshall
Answer: farm tractor