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Fresno Scraper (Patent Application)

The Fresno Scraper was invented in 1883 by the Scottish immigrant and entrepreneur James Porteous who, having worked with farmers in Fresno, California, had recognised the dependence of the Fresno Valley on irrigation and the requirement for a more efficient means of constructing canals and ditches in the sandy soil. In perfecting the design of his machine, Porteous made several revisions on his own and also traded ideas with William Deidrick, Frank Dusy, and Abijah McCall, who invented and held patents on similar scrapers. Porteous bought the patents held by Deidrick, Dusy, and McCall, gaining sole rights to the Fresno Scraper.

The design of the Fresno Scraper forms the basis of most modern earthmoving scrapers, having the ability to not only scrape and move a quantity of soil, but also to discharge it at a controlled depth, thus quadrupling the volume which could be handled manually.

The blade scooped up the soil, instead of merely pushing it along, and ran along a C-shaped bowl which could be adjusted in order to alter the angle of the bucket to the ground, so that the dirt could be deposited in low spots.

This design was so revolutionary and economical that it has influenced the design of modern bulldozer blades and earth-movers to this day.

Between 1884 and 1910 thousands of Fresno scrapers were produced at the Fresno Agricultural Works which had been formed by Porteous, and used in agriculture and land levelling, as well as road and railroad grading and the general construction industry. They played a vital role in the construction of the Panama Canal and later served the US Army in World War I.

It was one of the most important agricultural and civil engineering machines ever made. In 1991 the Fresno Scraper was designated as an International Historic Engineering Landmark by the American Society of Mechanical Engineers. It is featured prominently in the Fresno Metropolitan Museum.

• An ASME Historic Mechanical Engineering Landmark http://www.asme.org/history/roster/H158.html
• Engines of our Ingenuity, The Fresno Scraper http://www.uh.edu/engines/epi353.htm