A History of Dempster Windmills

Dempster Windmill

NPS Photo

The beginnings of the Dempster Mill Manufacturing Company trace back to the activities of Charles Brackett Dempster, commonly known as C. B. Dempster. In 1878, C. B. Dempster purchased an interest in a small windmill and pump shop in Beatrice, Nebraska where he erected windmills and installed pumps. There was no better way for him to study the merits of various windmill designs on the market at the time.

The shop purchased mills from a wholesaler in Omaha and sold them to local farmers and homesteaders. Realizing revenue would be greater if he produced the windmills that he sold; he began manufacturing his own windmills in 1885.

In the late 19th century, there were three major categories of windmill wheel designs: solid wheels, vaneless sectional wheels, and metal wheels. Dempster produced mills in all three categories until the mid-1920’s. At that time self-oiling metal mills became popular enough to stop production of all non-oiling mills. Along with producing oiling metal windmills, Dempster produced the only widely distributed oiling vaneless windmill, the No. 14 Vaneless.

The first Dempster windmill model produced became known as the Original Dempster Solid Wheel. Solid-wheel windmills have a rigid wooden wheel. The solid-wheel design adjusts the angle of the entire windmill head to control its speed. In slow winds, it will point into the wind for maximum efficiency. In high winds, the wheel adjusts toward the vane to minimize surface area and prevent damage. Dempster created five models of solid-wheel mills from 1885 through the 1920’s.

Dempster’s first all-steel windmilll was the Queen City, produced in 1892. These early steel mill designs included open back-gears instead of a direct-stroke mechanism allowing it to pump more in light winds. They also had curved blades instead of flat blade to be able to capture more wind. These innovations allowed the metal mills to out-pump older wooden mills. Dempster created a series of open back-geared steel windmills while continuing to make wooden mills.

By the 1880s, wooden vaneless windmills were growing in popularity across the central Great Plains. These windmills had hinged sections that could pivot in and out of the wind individually. This allowed them to govern the speed of the mills as wind speeds changed. Because they had no vanes or tails to direct them into the wind, their wheel operated downwind. The first Dempster vaneless windmill was produced in 1892. For over fifty years, the Dempster Mill Manufacturing Company produced a range of wooden vaneless windmills.

The market vanished for traditional style mills in the early 1920s, as consumers began to prefer self-oiling mills. Self-oiling windmills had an enclosed gearbox with an oil-bath that would continuously lubricate the mill. This meant maintenance on these mills was minimal, requiring oil about once a year. Dempster Mill Manufacturing Company produced its first of several self-oiling windmills in 1922 with the No. 11 Self-Oiling Windmill. The most popular windmill created by Dempster Mill Manufacturing Company was the No. 12 Annu-Oiled Windmill, manufactured for over eighty years with minimal modifications.

Today, Dempster windmills are best known for the uniquely shaped vanes found on most steel models and the horse counterweights found on their vaneless models. Models No. 1 & 2 had long-tailed horse weights while No. 3, 4 & 14 had short-tailed horses.

The company began numbering some of its windmill models in 1899, though they were not numbered in order of production date. Noticeably missing is model No. 13, perhaps due to superstitious beliefs associated with the number. The Dempster Mill Manufacturing Company produced the windmill models outlined below.

Windmill Model Chart

Start Date	End Date	Model Name	Material	Wheel Diameter, ft.	Replaced By
1885	1909	Original Dempster Solid Wheel	Wood	10, 12	Dempster No. 9 Solid
1892	1896	Queen City	Steel	8	Improved Queen City
1892	1900	Original Dempster Vaneless	Wood	10, 12, 14	Dempster No. 1 Vaneless
1892	1894	Beatrice	Wood	10, 12	New Era
1894	1897	Improved Queen City	Steel	8, 9, 10	Dempster Steel
1895	1917	Dempster Vaneless Irrigator	Wood	14, 16	N/A
1895	1917	Dempster Double-Stroke Vaneless Irrigator	Wood	14, 16	N/A
1896	1898	Dempster Steel (1896-97 & 1897-98 styles)	Steel	8, 10	Improved Dempster Steel
1899	1903*	Improved Dempster Steel	Steel	8, 9, 10	Dempster No. 6 Steel
1899	1906	Dempster No. 1 Vaneless	Wood	10, 12	Dempster No. 2 Vaneless
1900	1903	New Era	Wood or Steel	10, 12	Dempster No. 5 Solid
1903	1909	Dempster No. 5 Solid	Wood	10, 12	Dempster No. 9 Solid
1903	1906*	Dempster No. 6 Steel	Steel	6, 8, 10, 12	Dempster No. 7 Steel
1904	1922	Dempster No. 7 Steel	Steel	6, 8, 10, 12	N/A
1905	1909	Dempster No. 2 Vaneless	Wood	10, 12	N/A
1906	1917	Dempster No. 3 Vaneless	Wood	10, 12	Dempster No. 4 Vaneless
1906	1908	Arrow Steel	Steel	8	Dempster No. 8 Steel
1907	1917	Dempster No. 8 Steel	Steel	6, 8, 10, 12	Dempster No. 10 Steel
1908	1925	Dempster No. 9 Solid	Wood	10, 12, 14, 16, 18	Dempster No. 11 Self-Oiling
1914	1925	Dempster No. 10 Steel	Steel	6, 8, 10, 12	Dempster No. 12 Annu-Oiled
1916	1925*	Dempster No. 4 Vaneless	Wood	10, 12	Dempster No. 14 Annu-Oiled Vaneless
1921	1929	Dempster No. 11 Self-Oiling	Wood or Steel	10, 12, 14	Dempster No. 12 Annu-Oiled (Timken bearings)
1922	1924	Dempster No. 12 Annu-Oiled (Babbitt & Hyatt roller bearings)	Steel	8, 10	Dempster No. 12 Annu-Oiled (Timken bearings)
1923	1941	Dempster No. 14 Annu-Oiled Vaneless	Wood	10	N/A
1925	1984*	Dempster No. 12 Annu-Oiled (Timken bearings)	Steel	6, 8, 10, 12, 14, 16	Dempster No. 12A & B Annu-Oiled
1927	1941	Dempster No. 15 Annu-Oiled	Steel	8, 10, 12	Dempster No. 16 Annu-Oiled
1931	1984*	Dempster No. 12A Annu-Oiled	Steel	8	Dempster No. 12B Annu-Oiled
1936*	1960*	Dempster No. 16 Annu-Oiled	Steel	6, 8, 10	N/A
1982	2009*	Dempster No. 12B Annu-Oiled	Steel	6, 8,10, 12, 14	N/A

* Approximate Date

Sources

• Baker, T. Lindsay. 1984. A Field Guide to American Windmills. Norman, Oklahoma: University of Oklahoma Press.
• National Park Service. Homestead National Monument of America. Dempster Mill Manufacturing Company Records, 1878-2010.

Prepared by Amy Neumann, 2019