HOUTMAN’S ABROLHOS. 135 
arrival shortly after from Batavia in the frigate “Sardam,” that the conspirators 
designed to seize his ship. Two boat-loads of armed men, in fact, put off 
with this intention, but on being threatened by Captain Pelsart that he would 
sink them with his big guns if they did not immediately throw their arms 
overboard and surrender, they gave in. They and the remainder of the mutineers 
were captured, and all the participators in the previous massacres were summarily 
executed. 
A very considerable amount of treasure was on board the “ Batavia” when she 
was lost. Captain Pelsart succeeded in recovering all the jewellery and other valuables 
which had been appropriated by the mutineers, and likewise in raising from the 
wreck five out of the six chests of silver coin that were being brought out to Batavia. 
The sixth one is supposed to be still somewhere immersed among the coral reefs 
Numberless relics from the numerous wrecks that have occurred on Houtman’s 
Abrolhos, including a gun, cannon shot, coins, pipes, glass and earthenware, etc., 
have been already discovered, more especially on Gun and Rat Islands, during the 
process of excavating the guano which has accumulated there in large quantities, 
and a large number of these are now on view in the Perth Museum. Possibly 
the missing chest, or the bulk of its contents, may yet reward a persevering search. 
To proceed with the more legitimate subject of this Chapter, it is desir- 
able in the first instance to give a brief account of the precise geographical 
position and other essential details concerning the island group under discussion. 
Topographically defined, Houtman’s Rocks or MHoutman’s Abrolhos consists of a 
little archipelago, for the most part of coral formation, situated between latitudes 
28° 15” and 29° S., some thirty miles off the mainland coast of Western Australia 
and immediately opposite Champion Bay and the thriving port of Geraldton. 
More closely examined, the Abrolhos archipelago is found to be separable into four 
secondary groups, characterised in order from north to south as the North Island, 
Wallaby, Easter, and Pelsart groups. With the exception of the Wallaby group, 
which contains plutonic rocks corresponding in character with those of the mainland, 
and having an elevation of some thirty or forty feet, the larger residue is entirely 
of coral formation, while reefs of considerable extent also encircle the Wallaby series. 
Their composition, as manifested, more particularly in the islets of the Easter and 
Pelsart groups, consists of hard coral limestone conglomerate, undermined and 
weathered on its exposed aspects into low overhanging cliffs and promontories 
often of the most fantastic shape, which frequently show embedded in their eroded 
