Early 20th Century Root & Van Dervoort Type E 8 HP Engine

 This engine (serial #E2165) was made by the Root & Van Dervoort Engineering Company in East Moline, Illinois. Started at the end of the 19th century by Orlando J. Root and William H. Van Dervoort, the company was incorporated in 1900. Root & Van Dervoort produced engines until around 1919, shifting its focus to its automobiles, including the R & V Knight.
 The nameplate for this engine has two patent dates:
July 14, 1903, corresponding to patent 733752, a sparking-device governor for gasoline engines developed by Orlando J. Root, which you can view as a pdf here; and
May 3, 1904, corresponding to patent 759193, a liquid fuel pump developed by Orlando J. Root, which you can view as a pdf here.

 Although it's difficult to see from the walkway, there is an oil cup sticking up out of this engine's top. That oil cup was made by the Michigan Lubricator Company in Detroit. The Gade engine and the 6 HP Fairbanks-Morse engine in this exhibit also have oil cups made by the Michigan Lubricator Company.