Stump-jump plough

[3] Grubbing the mallee lands was laborious and expensive £2–7 per acre,[6] and the government offered a £200 reward for the invention of an effective machine that would remove the stumps.

This was a heavy roller which was dragged over roughly cleared ground by horses or bullocks, crushing small trees, undergrowth and new shoots.

This process was known as mullenising,[7] as the invention of the device was attributed to an Irish-born farmer from Wasleys called Charles Mullen.

[8] Mullen devised a contraption which included a heavy roller dragged behind a pair of logs fixed together to create a V-shape.

[14][15] Later that same year, Richard Smith demonstrated a single-furrow stump-jump plough which included a chain that dragged the bottom of the ploughshare back into the ground, known as the "bridle draught".

It became used throughout the British Commonwealth, and completely changed agricultural practices where it was adopted, as it allowed crops to be grown without removing stumps and rocks, thus saving a lot of work and time.

Unfortunately, Richard was only able to afford temporary registration of his invention, and others (including his brother Clarence, who had been an early sceptic) started making their own versions and earning profits on them.

[21] Albert Arnold (born in 1856 at Gawler, SA) reportedly improved on the design of the plough while doing his apprenticeship and working as a farmer in South Australia before moving to Sydney in 1882.