He was afterwards transferred to the geology department, and in December 1901 accompanied Professor F. T. Gregory on his expedition to Central Australia. In the preface to The Dead Heart of Australia Gregory paid a special tribute "To my assistant Mr Grayson on whom much of the hard work of the expedition fell".
He was later moved to the geology department, and in December 1901 accompanied Professor F. T. Gregory on his expedition to Central Australia. In the preface to The Dead Heart of Australia Gregory expressed special appreciation "To my assistant Mr Grayson, who bore much of the challenging work of the expedition."