Last updated: July 13, 2019
Article
A History of Dempster Windmills
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 |
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