The voyage began at Brisbane in April, extended northward to the Hope Islands and ended at Cooktown in May. Unfortunately, he had come to Australia in the height of the trade-wind season, and the almost constant gale greatly hindered the work of his expedition. Indeed, during more than a month of cruising he could spend only three days on the outer reefs, and the dredging and study of marine life which he had hoped to carry out were practically abandoned.
He concluded that the many islands and submerged flats off the Queensland coast were once connected with the mainland, but have been separated from the continent by erosion and denudation. After the formation of these flats and islands corals grew upon them. The recent reefs have been elevated at least ten feet, and do not owe their contours to subsidence, yet they form true atolls. The inner channels of the Barrier Reef are maintained free of corals by the great amount of silt held in suspension in the water or deposited to form a blue mud over the bottom. Thus there appears to be nothing in the Great Barrier Reef region to lend support to Darwin's theory of coral reefs. A tangible result of this expedition was the enriching of the museum at Cambridge by a great collection of Barrier Reef corals gathered under Alexander Agassiz's auspices by H. A. Ward.
His experience in Australia taught him to avoid the trade-wind season and henceforth his expeditions to coral seas were timed so that he cruised among the reefs in the late spring and early summer months when the trades have died out into the long hot days of calm which precede the coming of the hurricanes. This interval when the torrid sea is sleeping gave him the opportunity to land on many a jagged shore that defied approach at other seasons. He then could wade through the still waters over the coral reefs, and unravel at his will the secrets of the atolls, composed as they are of wave-tossed fragments that once were shells of mollusks or skeletons of creatures of the reefs. His overmastering interest carried him to the shores of hundreds of these distant atolls where the cocoa-palm, the Pandanus and the fishes of the reef afford the only sustenance for man, where there are no hills or streams and the land is only a narrow strip across which one hears constantly the roar of heavy breakers.
These years of cruising accentuated his already predominant self-reliance, for the commander of a marine expedition must needs be an autocrat by profession. He was accustomed to command and to be obeyed and his relation to the Harvard Museum during these later years was in miniature similar to that of Bismarck to the German empire. Indeed, there was a strange physical and mental resemblance between Alexander Agassiz and Bismarck. Fearless, resolute, quick to anger, definitely purposeful and full of resource, they were closely akin in character, and indeed there seemed much in common between