Designer credit split but South Australians come up with the stump-jump plough in 1870s for the mallee farming problem

The Yorke Peninsula town of Ardrossan memorial to Clarence Smith's part in inventing and making the stump-jump plough.
The stump jump plough invented by Richard Bowyer Smith and his brother Clarence – or James Winchester Scott – in South Australia in the 1870s solved a major problem in cultivating mallee lands. Mallee scrub that originally covered much of southern Australia was difficult to clear, quickly regrew, and left big roots even after burning.
The South Australian government was offering mallee scrub land leases in 1866 with a purchase option after 21 years at the price of £1 per acre but grubbing the scrublands was costly, at about £2 per acre.
By 1878, the government offered £200 for an effective mechanical stump puller. Many devices were tried in contests near Gawler but none was as effective as three skilled axemen.
Mullenizing (named after Wasleys farmer Charles Mullens) became popular to clear scrub. This involved dragging a heavy roller over roughly cleared ground to crush young shoots; the field was then burnt, and a spiked log was run over the ground, and a crop of wheat sown. The next season, the stubble and mallee regrowth was again burnt, and eventually the mallee died, though stumps remained.
An apprentice J.G. Ramsay & Co. of Strathalbyn, Richard Bowyer Smith and his brother perfected their stump-jump plough in 1876 on Yorke Peninsula. The plough had blades that rose out of the ground when they hit a mallee stump. Used with mullenising, the plough was hailed as “complete revolution” in cropping the mallee lands.
The Smiths were controversially credited as the stump-jump plough inventors, in 1883, by the South Australian parliament, Controversially, because James Winchester Scott, a prolific inventor from Alma in the mid north, had also come up with a stump-jump plough, in 1877, to go with his cultivator, slasher, scarifier and double furrow inventions. Scott and manufacturers the Mellor Brothers, who refined his design, lodged the first stump-jump plough patent in Victoria.