This represents an error of around ten degrees of longitude. The first known appearance of the Tryal Rocks on a map was in 1627, when Hessel Gerritsz published his "Caert van't Landt van d'Eendracht" ("Chart of the Land of Eendracht"). In the extreme bottom left corner of this map is a feature labelled "Hier ist Engels schip de Trial vergaen in Iunias, A° 1622" ("Here the English ship Trial was wrecked in June 1622"). Numerous Dutch and English sailors searched for the rocks over the centuries. The first attempt was in 1636, when two Dutch ships were sent to search for the Tryal Rocks at their purported location. Sickness prevented William Dampier from searching for the rocks in 1700; on 11 June of that year he wrote: "I kept on my course to the westward till the 15th, and then altered it. My design was to seek for the Tryal Rocks; but, having been sick 5 or 6 days without any fresh provision or other good nourishment aboard, and seeing no likelihood of my recovery, I rather chose to go to some port in time than to beat here any longer." The Tryal Rocks continued to be marked on charts, but gradually sailors began to doubt their existence. In 1705, the captain of the "Jane" wrote in his journal: "Hove to, according to custom, on account of the Tryal Rocks (if they exist), for although they are reported to extend 20 league in length I was informed by the Commodore of the Dutch Ships... that he had never heard of these rocks being seen." He went on to correctly surmise that "If they exist they must lie much farther east than in the route toward Java Head." Matthew Flinders undertook a thorough search for the Tryal Rocks in April 1803, but found nothing, and concluded that "It should appear from our examination, that the Trial Rocks do not lie in the space comprehended between the latitudes 20° 15' and 21° south, and the longitudes 103° 25' and 106° 30' east." Consequently, the British Admiralty declared them non-existent. In 1818, the British brig , captained by Lieutenant Ritchie, encountered the true Tryal Rocks. They were not recognised as such, however, as the Tryal Rocks were then thought not to exist, and they had previously been thought to be well to the west of Ritchie's reef.