There are three monstrous compilations of the records of early travelers and explorers available via Google Books. Starting from the earliest, the first is Richard Hakluyt’s “The principall navigations, voyages, traffiques, and discoveries of the English nation, made by sea or over-land to the remote and farthest distant quarters of the earth at any time within the compasse of these 1600 years.” Hakluyt (1552-1616) was an Englishman who become interested in such things while at Oxford. He found and read all he could on the topic, and after 10 years began to publish what he had found. The first version of his monsterpiece was pubished in 1582 in 3 volumes, and the final 12-volume version was published under the auspices of the Hakluyt Society - founded in 1846 to perpetuate the labors of Hakluyt and his spiritual successors - in 1903-1905. All 12 volumes are currently available in PDF format.
The second of the compilations was put together by Samuel Purchas, a near contemporary of Hakluyt’s who based it in part on manuscripts left by Hakluyt and further included explorations of all nations. All 20 volumes of Purchas’s “Hakluytus Posthumus or Purchas His Pilgrimes, Contayning a History of the World in Sea Voyages and Land Travells by Englishmen and others” are also available in PDF format.
The last of the great compilations was John Pinkerton’s “General collection of the best and most interesting voyages and travels in all parts of the world, many of which are now first translated into English“, which was first published from 1808-1814. Of the 17 volumes in this series, all are available except for nos. 1 and 9. Pinkerton, an unexploded Scotsman, compiled the largest collection to that date which includes rare voyages not included in the earlier collections.
Unfortunately, the least useful feature of all three series is the ancillary material, and by “least useful” I mean that it’s for the most part nonexistent. If I ever get a round tuit (ho ho), I’ll add all three to my obscure books listing along with tables of contents.
Addendum: Well, we’re part of the way there.