One of the earliest speculations about unrecorded voyages to Australia comes from the memoirs of Joseph Mason, a convict who served his sentence in NSW in the 1830s. Mason’s handwritten memoirs remained almost unknown, but were finally edited and published in 1996 [Kent and Townsend 1996] and are an important source for Australian convict history as seen from the inside.
Mason was transported for participation in unrest arising from the social dislocations accompanying industrialisation in Britain. Perhaps because of his status as a political prisoner he reveals himself to be a thoughtful chronicler whose memoirs are quite different from the normal convict fare. He was assigned as a convict servant to Hannibal Macarthur at his Vineyard estate near Parramatta in 1831. Macarthur also had another grazing estate called Arthursleigh on the banks of the Wollondilly, south of Sydney, which had been established before official settlement was permitted within this area [Fletcher 2002].
In a section of his memoirs where he speculates about previous history of Australia, and whether the Aboriginal people were its sole former occupants, Mason says:
There is two spots of ground one about 30 miles to the south of any residence and the other on the bank of the Hunters River which I was informed by creditable witnesses as well as having seen the same in a book bear marks as if it had once undergone the operation of ploughing. The first of these lies in the road leading to the south of the colony and is always called the ploughed grounds. The blacks have been asked if they know what occasioned these spots [of] land to Assume their present shape but their are quite ignorant as to the cause Had any of their ancestors been acquainted with husbandry there certainly would have been more extensive marks of it remaining than these two spots of ground nor is it likely that the present race or rather generation should have been so retrograded from the path of industry as to possess not a single grain of corn an agricultural impliment, or the slightest notion of cultivating land. [Kent and Townsend 1996: pp. 121-2]