On the 28th of November 1605 the ship Duifken, commanded by Willem Jansz., put to sea from Bantam with destination for New Guinea. The ship returned to Banda from its voyage before June of the same year. What were the results obtained? What things had been seen by Willem Jansz. and his men? The journal of the Duifken's voyage has not come down to us, so that we are fain to infer its results from other data, and fortunately such data are not wanting. An English ship's captain was staying at Bantam when the Duifken put to sea, and was still there when the first reports of her adventures reached the said town. Authentic documents of 1618, 1623, and 1644 are found to refer to her voyage. Above all, the journal of a subsequent expedition, the one commanded by Carstensz. in 1623, contains important particulars respecting the voyage of his predecessors in 1605-6. [*] [* See pp. 28, 42, 43, 45 _infra_. I trust that these data will go far to remove COLLINGRIDGE'S doubt (Discovery p. 245) as to whether the ship Duifken sailed farther southward than 8° 15'.] On the basis of these data we may safely take for granted the following points. The ship Duifken struck the south-west coast of New Guinea in about 5° S. Lat., ran along this coast on a south-east course [*], and sailed past the narrows now known as Torres Strait. Did Willem Jansz. look upon these narrows as an open strait, or did he take them to be a bay only? My answer is, that most probably he was content to leave this point altogether undecided; seeing that Carstensz. and his men in 1623 thought to find an "open passage" on the strength of information given by a chart with which they had been furnished. [**] This "open passage" can hardly refer to anything else than Torres Strait. But in that case it is clear that Jansz. cannot have solved the problem, but must have left it a moot point. At all events he sailed past the strait, through which a few months after him Luiz Vaez de Torres sailed from east to west. [* As regards the names given on this expedition to various parts of this coast, see my Life of Tasman, pp. 90-91, and chart No. 3 on p. 5 _infra_.] [** See pp. 47, 66 _infra_.] {Page vi} Jansz. next surveyed the east-coast of the Gulf of Carpentaria as far as about 13° 45'. To this point, the farthest reached by him, he gave the name of Kaap-Keerweer [Cape Turn-again]. That skipper Jansz. did not solve the problem of the existence or non-existence of an open passage between New Guinea and the land afterwards visited by him, is also proved by the circumstance that even after his time the east-coast of the Gulf of Carpentaria was also called New Guinea by the Netherlanders. Indeed, throughout the 17th and 18th centuries the Dutch discoverers continued in error regarding this point. They felt occasional doubts on this head [*] it is true, but these doubts were not removed.