In 1871, he made a trip to the Northern Territory with his brother James to secure a property on behalf of George McLachlan.

About the same time Lewis left Burra for Adelaide, moving into the imposing residence 'Benacre' in Glen Osmond, built for William Bickford.

He acquired various pastoral properties in South Australia: Dalhousie Springs, Witchelina, Mount Nor'-West, Ediacara, Nappa Merrie, Coronga Peak, and Newcastle Waters, many in conjunction with Sir Thomas Elder.

[4] He was a member of the South Australian branch of the Royal Geographical Society and for seven years its president.

He married again on 5 July 1907 to widow Florence Margaret Toll ( – 23 February 1941), the youngest daughter of William Ranson Mortlock.