Article

A History of Dempster Windmills

Dempster Windmill Tail
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

Last updated: July 13, 2019