Moving islands

Following on from my post about Sandy Island, I found another example of a cartographic blunder. Not as dramatic, but still quite peculiar.

In the 1700s, Great Britain was a proud, sea-faring nation. It rose in influence until it could rightfully call itself a world power by the end of the century.

So it must have been with some surprise when Joseph Huddart travelled to the Scilly Isles of the coast of Cornwall, with a watch made by Arnold to help him measure longitude, he found that the previous co-ordinates for the islands were off by almost twenty minutes. Namely, the Scilly Lights were thought to be 49° 56' 0" N, 6° 46' 0" W but, in fact, turned out to be 49° 53' 36" N, 6° 19' 23" W.

Joseph Huddart

His discovery was confirmed two years later when angles to points in the Scilly Isles were measured from Land's End. It was not uncommon in those days for the co-ordinates of islands to be incorrect. The book “Tables of Positions...” by Purdy, published in 1816 contains many entries which are updated from previous erroneous figures, or are even an estimate given the available data, but those were mostly for isolated islands. As Mudge (quoted in Hudddart, 1821) wrote

“How in a maritime country like our own, where chronometers are in such constant use, so great an error as 26'37” in the longitude, should have remained undetected, excepting by one person, is surprising.”

Google maps showing the old location of the Scilly Isles

References:
Huddart, J. (the younger) (1821), "Memoir of the late Captain Joseph Huddart", W. Phillips, London.
Purdy, J. (1816) “Tables of the Positions, or of the latitudes and longitudes, of places, composed to accompany the 'Oriental Navigator,' or Sailing directions for the East-Indies, China, Australia, &c.”
Purdy, J. (1825) “Memoir, Descriptive and Explanatory, to accompany The New Chart of the Atlantic Ocean”

The search for Sandy Island continues

Recently, it was discovered (or undiscovered) that an island that had been included on maps for years did not exist. The story broke recently and even made it onto the BBC web site, and since then people have been trying to track down the history of this fictional island.

The blog at Auckland Museum has a chart that places its discovery in 1876 to a ship called Velocity, but the blog notes that the map came with a disclaimer warning readers of the accuracy of the positions of low-lying islands in that part of the ocean.

As a member of the army or armchair experts created by the internet, I set off on a voyage of discovery to find traces of this island for myself. It didn't take long to realise I was already walking in other people's footsteps as I found little new on the subject. I did, however, find on Google Books a volume dated 1851 that listed Sandy Island (New Caledonia) in its index.

So I was all excited that I'd found something that everyone else had missed, until I looked at the entry in closer detail. Unfortunately, this refers to a smaller Sandy Island which is much nearer the coast of New Caledonia and does, to my knowledge, really exist.

But, anyway, this is a beautiful story and it's a useful reminder that however important and established an authority may be on a subject, it doesn't hurt to check the basics.

Perhaps the fake Sandy Island kept itself in reference books simply by being in a place where no one would check, and by having a name identical to another island not so far away. You know, when I was growing up in Hertfordshire, I would sometimes see signs to a village called Ireland. I wished I'd checked if it was really there, and not some cartographer's quirk.