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Massey-Harris #20 Combine
Society: ASABE Main Category: Agricultural & Biological Sub Category: Equipment, Harvesting and Baling Era: 1930s DateCreated: 1938 Ford Museum Dearborn State: MI Zip: 48124 Country: USA Website:, Creator: Carroll, Thomas

Designated A Historic Landmark Of Agricultural Engineering The Massey-Harris No. 20 was the First Commercially- Successful Self-Propelled Combine Used to Harvest Small Grains Under a Wide Variety of Conditions, World-Wide. Engineered By Thomas Carroll, Chief Engineer, Aided by Robert Ashton and Albert Luke, Principal Assistants, it was First Marketed in 1938 by the Massey-Harris Company. This Combine Opened a New Era an Farm Mechanization and Revolutionized the Grain Harvesting Process. Forty-Four Years Later, This Same Harvesting Principle Continues to be Used Throughout the World.

Image Credit: Image Caption: Combine pictured at the Henry Ford Museum in Dearborn, MI Era_date_from:
Hydromatic Propeller
Society: ASME Main Category: Aerospace & Aviation Sub Category: Aerospace Era: 1930-1939 DateCreated: 1938 New England Air Museum
Bradley Intl. Airport
Windsor Locks State: CT Zip: 06096 Country: USA Website:, Creator: Hamilton Standard

Rapid development of aircraft design in the 1930s required many related innovations, including propeller design. The hydromatic propeller by Hamilton Standard marked a significant advance over the counterweight-type, controllable pitch propeller. The first test flight of the prototype took place in 1938: the public demonstration was made by a United Air Lines DC-3 over New York City on April 6, 1938. It played a distinguished role in allied combat aircraft in World War II.

Image Credit: Courtesy ASME Image Caption: An early example of propeller innovations, including variable-pitch control and feathering capability. Era_date_from: 1938
Bonneville Dam, Columbia River System
Society: ASCE Main Category: Civil, Electrical Sub Category: Dams, Power Generation, Power, Energy & Industry Application Era: 1930-1939 DateCreated: 1938 Colombia River Portland State: OR Zip: 97014 Country: USA Website:,-columbia-river-power---nav-system/ Creator: U.S. Army Corps of Engineers

The Bonneville Dam, Columbia River Power and Navigation System consists of 55 major projects on Oregon's Columbia River and is said to be the largest hydroelectric system in the world.

The Columbia River forms part of the border between Washington and Oregon and flows inland through the only waterway that crosses the Cascade Mountains. To harness the energy of the ninth longest river in North America, engineers developed unique design and construction approaches to overcome problems caused by depth of water, current velocity, and an irregularly-shaped river bottom.

Image Credit: Courtesy Flickr/Ann Larie Valentine (CC BY-SA 2.0) Image Caption: The impressive power of the Bonneville Dam Era_date_from: 1938
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