Cawker, Louis (1834-1908; Welsh)
The new floating battery, for the defence of Sydney Harbour 1867
State Library of Victoria (IMP24/01/67/8)
This print, published in the Illustrated Melbourne Post, 24 January 1867, illustrated a recently-invented device credited to an inventor named R.Rutter.
PF (acc.no.p.178.4-1: Section of a floating battery), under 1868
Details above via SLV catalogue (with photo)