Used by Ettore Alessandri who came to Australia in 1930's. He had land at Marlo and used this jack to clear the property of trees and stumps in 1940's and 1950's. The Trewhella Monkey jack was invented by the Trewhella brothers to help land clearance in Australia during the 1880's. Two jacks were made a 5 ton and a 10 ton. This item is a 10 ton model having two extension bars. The longer spear is used for larger tree work and the smaller spear for general work and small trees. Both models had two lifting claws at different heights. Th lower claw was useful for roots. The top claw was intended for going under loads and the bottom claw used for rolling timber. In 1929 the cost of the 10 ton model was thirteen pounds ten shillings.This item is an example of the machinery used by the early settlers to clear land. A 10 ton monkey jack. It has two extensions (spears) and two lifting claws. It has a detachable handle. 2033.1 is the main jack. 2033.2 is the handle. 2033.3 is the shorter extension and 2033.4 is the longer extension.On extension - BRITISH STEEL On main section - 10 TON MONKEY JACK PATENTED 1411-50 AUGUST 04 1412-50 AUGUST -05 ?????? JUL -06 12104-20 JUL-08 Trewalla Bros Trentham Vicrural monkey-jack trewhella agriculture machinery