In Dampier's time navigation as an art had scarcely made a stride since the days of Columbus and the Portuguese discoverers. The instruments for measuring the sun's altitude were the astrolabe, the cross or forestaff, and Davis's backstaff,—engines for mensuration ludicrously primitive, as will be supposed when viewed side by side with the sextant of to-day. The mariner made shift with these contrivances to determine his latitude within a degree or two, but he had no means of ascertaining his longitude. There were no chronometers, there was no portable Greenwich time, no aids whatever towards the solution of what was regarded down to the days of Maskelyne and the Commissioners of Longitude as the greatest marine problem that ever perplexed the mind. Apparently the old practice was to run down the parallels and then make direct easting or westing for the desired destination. Or they took “a departure,” as it was called, from any point of land, and calculated the meridians by the log. Or, as an alternative, the early navigators employed dead-reckoning, as we still practise it—that is, they found out a vessel's place on the chart by putting down her rate of sailing as it was to be ascertained at regular intervals by “heaving the log,” and by allowing for leeway and difference of courses. In Captain Thomas James's _Strange and Dangerous Voyage in the years_ 1631-32[4] there is included a list of the instruments provided by him for his undertaking to discover the north-west passage into the South Sea. A few of the items will furnish the reader with a tolerable idea of the primitive character of the nautical implements with which the mariner in the days of James, and later yet in the days of Dampier, embarked on his voyages into the remotest parts of the world in quest of new lands or in search of short cuts. James begins the list with “a quadrant of old-seasoned pear-tree wood, artificially made and with all care possible divided with diagonals, even to minutes. It was a four-foot at least (semi-diameter).” Next: “An equilateral triangle of light wood, whose radius was five-foot at least, and divided out of Petiscus's table of tangents.” “A quadrant of two-foot semi-diameter of light wood and with like care projected.” Then: “Four staves for taking altitudes and distances in the heavens.” The captain also took with him “a staff of seven-feet long, whose transom was four-foot divided into equal parts by way of diagonals that all the figures in a radius of 10,000 might be taken out actually.” “Another of six-foot near as convenient and in that manner to be used. Mr. Gunter's cross-staff, three Jacob's staves projected after a new manner and truly divided after the table of tangents, two of Mr. Davis's backstaves with like care made and divided.” These were the captain's instruments for measuring the height of the sun. Other items comprised “six meridian compasses ingeniously made; four needles in square boxes; four special needles (which my good