manufactured springs, axles and other small parts for railroad use. The first locomotive that Rogers' company assembled was actually built by Robert Stephenson and Company of England in 1835. This locomotive was the McNeil for the Paterson and Hudson River Railroad. It took another two years before Rogers received its first order for a complete locomotive. In 1837, the Mad River and Lake Erie Railroad ordered two locomotives from Rogers to form the beginning of the railroad's roster. The first of these two locomotives was the Sandusky, which became the first locomotive to cross the Allegheny Mountains (albeit by canal boat and not by rail), and the first locomotive to operate in Ohio. Sandusky included features designed by Thomas Rogers that had not been seen in locomotive construction to date. It was also the first locomotive to use cast iron driving wheels, and the wheels included built-in counterweights to reduce the amount of wear on the track caused by the weight of the driving rod and wheel all coming down at once during the wheels' rotations. Before Sandusky'''s construction, driving wheels were typically built with wooden spokes, much like wagon wheels. Some accounts also state that Sandusky was the first locomotive to feature a whistle, but this has since been proven false. Rogers was not working completely alone in American locomotive manufacturing. In 1837, in addition to building the company's first locomotive, Rogers also filled orders from fellow locomotive builders Matthias W. Baldwin (founder of Baldwin Locomotive Works) and William Norris (founder of Norris Locomotive Works) for locomotive tires of various sizes. Once Rogers started working on his own locomotives, however, no further orders from either Baldwin or Norris were forthcoming. Within Rogers' own shop, William Swinburne worked as the shop foreman until he moved on to form his own locomotive manufacturing company, Swinburne, Smith and Company in 1845. After Swinburne left Rogers, John Cooke also worked at the Rogers plant. Like Swinburne, Cooke later went on to form his own locomotive manufacturing firm, Danforth, Cooke & Company. Another engineer who worked at Rogers was Zerah Colburn, the well known locomotive engineer and, later editor and publisher. Colburn was, around 1854, "superintendent and/or consultant" at the works where he introduced a number of improvements in locomotive design. His assistant was William S. Hudson who succeeded Rogers after he died in 1856, and was responsible for further engineering enhancement. Hudson would