Sir Peter Scratchley was a colonial official who served as Commissioner of Defences for the Australian colonies in the 1870s. This book, published in 1887, two years after his death, is his review of the preparedness of Australia and New Zealand for invasion, should one come. In it Scratchley argued that following his advice over the previous decade, which suggested defensive works near ports and the use of torpedoes and mines, Australia was well prepared for an invasion. New Zealand however, still needed further work.
In 1884, Scratchley was appointed special commissioner for the newly established colony in New Guinea. Following his arrival at Port Moresby, he began to introduce policies beneficial to the Indigenous population in the colony, believing that it would better serve the British Empire if it was governed by Indigenous people loyal to the Crown and if Indigenous groups had their lands protected from incursion, rather than being ruled by white colonial officials and being open to exploitation by private individuals.