The second major anomaly with maps derived from Pont’s survey is that the Outer North Isles of Orkney appear to have been rotated anti-clockwise through 90 degrees about a point roughly centred on Eday (Fig. 1). An explanation for the rotation of the northern isles may lie in the collection of residual manuscript maps by Pont now held by the National Library of Scotland. Unfortunately the original manuscript maps of Orkney no longer exist but those of other areas which remain tend to be on small pieces of paper. Some of these are composites of smaller fragments apparently stuck together.
The likeliest explanation for the rotation of the Outer North Isles of Orkney in the Pont-derived maps appears to be that Pont’s manuscript version of the North Isles was prepared on a separate piece of paper from that used for mainland Orkney. The rotation could then have occurred during compilation of the final map of the county if the northern section was attached to the southern at 90 degrees to the correct orientation. This is rendered more likely by an appreciation that nearly forty years appear to have elapsed between Pont’s original survey and the first engraving of it by W. Blaeu to yield the map of Orkney we know today. Furthermore, evidence suggests that Pont had been dead for about 15 years before the map was engraved and therefore that his personal knowledge of the relationships of the various sections would not have been available to the engravers.
When an attempt was made to correct this anomalous alignment of the Outer North Isles by simply rotating this region of the map clockwise through 90 degrees, the resulting “original” error was reduced by nearly four-fold. Fig. 1 illustrates these changes and indicates that much of the uncorrected error was associated with omission of the high ground in the West Mainland resulting in the southerly displacement of the northern coastline of the West Mainland and of the island of Rousay .
Later Maps Derived from Pont’s Survey
The fate of Pont’s survey of Orkney between completion and its first publication by Hondius remains obscure. During the first half of the seventeenth century, there was rivalry between the Dutch publishing houses of the Hondius and Blaeu families and both produced a combined map of Orkney and Shetland based on Pont’s surveys. The error correlation between the maps produced by the two houses was 99%.
Pont Maps (2)
Evidence from Pont’s maps of mainland Scotland suggests that he tended to restrict his progress to lower ground and he included relatively little survey evidence from sparsely populated hill regions. This concentration on lowland populated areas probably explains the under-representation of the hilly ground in the north west of the Orkney Mainland and the southerly displacement of Rousay.