Editing Plough (section)

===Stump-jump plough===
{{Main|Stump-jump plough}}

The [[stump-jump plough]] was invented in 1876 by Australian [[Richard Bowyer Smith]] alongside his brother [[Clarence Herbert Smith]]. It is designed to break up new farming land that contains tree stumps and rocks expensive to remove.<ref>{{Cite archive|first=Clarence Herbert|last=Smith|item-url=https://digital.collections.slsa.sa.gov.au/nodes/view/2478|type=Manuscript|date=1876, 1880|item-id=PRG 432/4|title=Stump Jump Plough|collection=Digital Collections|institution=State Library of South Australia|access-date=August 4, 2023}}</ref> It uses a moveable weight to hold the ploughshare in position. When a tree stump or rock is encountered, the ploughshare is thrown up clear of the obstacle, to avoid breaking its harness or linkage.<ref>{{Cite news|last=Coleman |first=Dudley |date=January 22, 1948 |title=Richard Smith and his Stump Jumping Plow |pages=18, 23 |work=The Adelaide Chronicle |url=https://trove.nla.gov.au/newspaper/article/93182324/8704492 |access-date=August 4, 2023}}</ref> Ploughing can continue when the weight is returned to the earth.<ref>{{Cite archive|first=Debbie|last=Rudder|item-url=https://collection.maas.museum/object/214026|type=Object|date=1882–1883|item-id=B526|title=Model Stump Jump Plough|collection=Powerhouse Collection|institution=Powerhouse Museum|access-date=August 4, 2023}}</ref>

[[File:Disc ploughs from The Powerhouse Museum Collection.jpg|thumb|[[Disc plough]]s in Australia, c. 1900]]
A simpler, later system uses a concave disc (or pair of them) set at a wide angle to the direction of progress, using a concave shape to hold the disc into the soil{{snd}}unless something hard strikes the circumference of the disc, causing it to roll up and over the obstruction. As this is dragged forward, the sharp edge of the disc cuts the soil, and the concave surface of the rotating disc lifts and throws the soil to the side. It does not work as well as a mould-board plough (but this is not seen as a drawback, because it helps to fight wind erosion), but it does lift and break up the soil (''see'' [[disc harrow]]).{{citation needed|date=February 2022}}