Six unpublished Admiralty charts (L945-L950) are believed to be preliminary drafts for Admiralty Chart 1375, published in 1841. The six charts show what appears to be the track of the Beagle during its Galápagos visit, but this track does not always agree with the bearings found in the logs, nor is it seen on the published chart. Some apparent contradictions between the six charts, the logs and other records are reviewed below. Each date below is a link to the entry in the log for that date, and unless otherwise noted, all entries cited here are taken from the Captain's Log. All references to FitzRoy's Narrative are taken from Proceedings of the Second Expedition … (Volume II of the four-volume Narrative)—JW.
View map showing Beagle track (or press “M” key while reviewing entries below).
14 September: The noon log entry gives the latitude and longitude as 1°53' S and 88°13' W, as indicated by the on the detail view. The bearing and distance to Lord Hood's Island are given as N 45° W, and 62 miles, and this position is indicated by a yellow dot. This entry is assumed to be an estimate, because the maximum height of Hood Island is 675 feet and therefore it is not visible beyond about 32 miles. (Colored circles surround both islands to indicate their visibility limits.) However, the estimate does not agree with the given latitude and longitude: In fact, if the Beagle were at the indicated position, the bearing and distance would in fact be approximately N 72° W and 111 miles.
15 September: The noon log entries are 1°07' S and 89°01' W ( ), and the bearing and distance to Chatham Island are NW and 10 miles (yellow dot). But again the entries are contradictory: if the ship were at the indicated position, the bearing and distance would be about N 70°W and 41 miles. The noon Course entry is given as N 46° W, and this is exactly the course calculated by GPS (Garmin III+) between the noon bearings taken on 14 and 15 September. Thus, the positions recorded on these two days appear to be consistent. They also permit the bearing taken at 10:00 am on 15 September to be applied to Chatham Island, as shown on the detail view. However, if the Beagle were indeed at the position indicated by today's noon latitude and longitude entries, and thus some 41 miles distant from the island, it seems unlikely that an observer would grossly understate the distance at 10 miles.
The 6:30 pm entry of “Woods” is in error, and should be “Hood's.”
16 September: The “Woods/Hood's” error is repeated in the 5:00 am entry, but the same island is correctly identified in the 11:00 am entry which appears to have been written by the same hand.
The noon “Yawl” entry is followed by four bearings with no time indicated. This is followed by bearings taken at noon which place the Beagle some 20 miles removed from the previous sets. Presumably the yawl entry was written after the bearings were taken, even though it appears above them in the log. Darwin's Diary states that the yawl left “in the evening” which therefore makes it difficult to satisfactorily resolve these discrepancies.
18 September: According to FitzRoy (Narrative, Volume II, p. 488), “ … we anchored … near the north-east end of the island.” That, together with the S 50° W bearing to Kicker Rock, suggest that the noon N 76° E bearing to Mt. Pitt should actually be S 76° E. If the bearing were in fact correct as written, Mt. Pitt would not have been visible.
19 September: Chart L945 shows a zig-zag track to the northeast of Chatham island, followed by a lengthy segment that takes the Beagle eastward beyond the border of the chart, and then back in again. Yet all three logs show no entries that would support this detour. In fact, FitzRoy states that the ship “Sailed round the north-east extremity of the island, and worked to the southward against a tide, or rather current, setting strongly to the north-west.” This would suggest that the Beagle worked down the coast of the island, well within site of the shoreline. Furthermore, that shoreline is shown in some detail (though not with the accuracy found elsewhere), and this too would indicate the ship was closer to shore than the track shown on the chart. However, there are no detailed soundings written on the chart from the northeast tip to the vicinity of Fresh Water Bay, and that would suggest that the Beagle was indeed at some distance from the shore.
20 September: No details are given to explain why David Walton was left on the island without food or water. Since he was apparently willing to return to his ship a few days later, his stranding may have been accidental.
23 September: The Narrative does not agree with the log. The latter places the Beagle south of Barrington in the evening, and early the next morning it was still closer to Barrington than to Charles. In any case, the ship was under sail between Barrington and Charles, not between Charles and Hood as stated in the Narrative.
29 September: Somewhat to the south of Point Christopher on Albemarle Island, an inscribed semi-circle on Chart L946 suggests the Beagle took an unusual detour away from the coast and then back again. A similar though smaller semi-circle is also seen to the north of Point Christopher. Again, there is nothing in the logs nor in the Narrative to explain such odd detours.
The 6:40 pm centre of Narborough N by E bearing would place the Beagle northwest of its apparent actual position.
30 September: The Ship's Log contradicts itself. In the hourly entry columns, 4:00 - 9:00 pm shows “Running along the NE side of Narborough Island.” And at 10:00 pm, “Moored in Blonde Tagus Cove.” But the “Remarks” column (right hand side of page) shows the entry “6 - 18 [6:18 pm?—JW] Came to in Tagus Cove.”
1 October: The corrected “Moored in Blonde Tagus Cove” entry is repeated in the hourly entry column for the morning, but written “Moored in Tagus Cove” in the afternoon.
It is unclear why the Ship's log entries alternate between “Blonde” and “Tagus” on two successive days. For both days, the Master's log shows an uncorrected “Blonde Cove” while the Captain's Log shows “Moored in [blank space] Cove.”
4 October: The ESE bearing to James Island should probably be SSE. In order to see James at ESE, the Beagle would have had to be on the east side of Albemarle, approaching volcan Alcedo. But in FitzRoy's Narrative he remarks about a north-westward current, and being pushed 40 miles to leeward.
5 October: Apparent errors in the 1:10 pm bearings make it impossible to determine their validity. For example, given the Beagle's approximate position, Tower Island was far too distant to be seen at that time. To support this view, the darkened circle surrounding Tower has a radius of approximately 32 miles, beyond which the island would not be seen due to the curvature of the earth. Therefore, the “Towers SE ½ E” bearing is believed to be to Abington, or possibly to Bindloe. However, it still can't be completely resolved with the two bearings to Abington which follow it in the logs. In addition, the bearing to “High land on Albemarle” (indicated by “?”) is too ambiguous to be plotted with certainty. It's possible the Abington and Albemarle bearings were taken later in the day, but there just isn't enough information here to make a reasonable guess.
As written in the logs and shown in red on the detail view, the bearings to Abington and Tower place the Beagle far to the north—and well beyond the 32-mile visibility limit—of Tower Island. It is therefore apparent that the name of at least one of these islands was written in error. If Tower should have been written as Bindloe, then the green set is correct. However, if Abington should have been written as James, then the black set is correct and this seems more likely. It places the Beagle well within Tower's visibility limit, and agrees with subsequent bearings to Tower taken later in the day and with the track drawn on Chart L949. After sighting Tower, the Beagle may have continued its easterly course to give it room, after tacking, to pass the island at close range on the way back.
7 October: The 11:00 am through 1:00 pm entries in the Captain's and Ship's logs do not name the island to which the bearings refer. The noon bearings in the Master's log duplicate those in the Captains's log, but add the name of the island cited as James. However, given the ship's position, that designation is incorrect. The 2:00 pm entry cites Tower by name. Those following it were presumably taken later in the day, although no time is given. The references to a “Bradbier's” island [Captain's and Ship's log only] suggest uncertainty about its identity. The source of the “Bradbier's” name is unknown.
With reference to Tower Island, the 7 October entry in FitzRoy's Narrative states that “ … We passed it about noon, and Bindloes at sunset.” This supports the assumptions made above about the identity of the islands not named in the logs.
10 October: See the detail map for several interpretations of the 8:00 am bearings.
The sunset bearing to Mt. Pitt is not plotted, pending clarification. The entry shows a horizontal line with “52,,30” above it and “79 E.—” below.
The 11:40 pm bearing is assumed to be W ½ S.
18 October: Although five bearings are listed in the 4:00 pm entry, the fourth is a repetition of the first, and the fifth does not agree with the first three. Therefore, the fourth and fifth are assumed to have been taken after 4:00 pm. They are not plotted on the chart because the fifth bearing would place the Beagle far from its assumed location.
19 October: The 8:00 am entry marks the first appearance of the name “Bindloes” in the log. Previous entries (6-7 October) referred to it as “Bradbier's” or left the name blank.
Surveys taken by H. M. S. Beagle during the first few years of its voyage were sent to England from various locations in South America, and received by the Hydrographic Office at intervals between 1832 and 1835. Surveys taken along the Chilean coast, in Galápagos and later in the voyage were all received in 1837. Presumably, these documents remained on the Beagle until it returned home in late 1836.
The eight detail views (L951-L958) and six charts (L945-L950) of Galápagos were all received on 7 May, 1837. The former are thought to have been drawn onboard the Beagle while it was visiting the indicated locations. By contrast, the style and condition of the charts suggest they are the work of a professional cartographer. In comparing one of them—L948— with Admiralty Chart 1375, the former was placed on top of the latter, and then a section was cut away to reveal Chart 1375 lying beneath it. The close agreement between them suggests that L948 and the other five charts in the series were preliminary drafts for Admiralty Chart 1375, drawn by the same hand that prepared Chart 1375.
If this assumption is correct, then the six charts were not drawn by FitzRoy himself, and therefore, neither was the track of the Beagle seen on these charts. It may have been added by someone in the office of the engravers (J. & C. Walker), perhaps working from information found in the three ship's logs.