01 March 2015

Scottish sundials

In the Edinburgh Botanical Garden, a modern sundial (running two hours fast!*) -
Made by Ian Hamilton Findlay with Michael Harvey in 1975, installed at Inverleith House in 2013.

In the National Museum of Scotland, two polyhedral dials -

Sundials were very popular in the orderly gardens around castles and mansions, particularly in Scotland (said the label).

The lecturn sundial above is from Cantray, Croy, Inverness-shine, and has 13 dials on five faces, showing the time in Peking, Goa, Bengal, Ozaca, Troy, Smyrna, Cairo, Jerusalem, Syracuse, Naples, Rome, Paris and Cantray.

But 13 dials on five faces are nothing compared to this beauty, an obelisk sundial with 76 faces near Crieff -
The photo is from a comprehensive and fascinating website called Sundials of Scotland.

Both obelisk and lecturn sundials are thought to have originated in Scotland.

This one was made in Scotland in the late 17th century and sold at Christies in 2011 for £16,000.

The NMS website shows its wide-ranging holdings of sundials - 57 - many portable and most made outside Scotland. But it doesn't include the lectern sundials shown above.

I contacted Dennis Cowan (Sundials of Scotland) and he helpfully replied:

There can be any number of reasons why the sundial in the Botanics is showing the wrong time. A sundial has to be designed for its particular location and it could be that this was not the location for which it was originally designed, in which case it would not be accurate.

It may be wrongly designed but as it was made by IHF this is probably not the case.

The gnomon is only fixed by a single point and it may have moved. If it was not in its designed position then it would be inaccurate.

It should also be noted that because of the earths eliptical orbit and its 23 deg tilt, the sun is not in the same place at the same time every day, so any sundial can be up to 16 minutes fast or slow depending on the date. The Equation of Time gives details of how many minutes fast or slow on any given date. (Google it for more details - Wikipedia is good). At the moment its about 12 minutes slow. Also each degree west of Greenwich the sundial is, it will be 4 minutes slow. For Edinburgh this would be 14 minutes. So that could account for 26 minutes of its slowness. In addition it may be showing British Summer Time which would account for another hour of its slowness.

Nothing definite of course but I hope that helps.

By the way it is a south declining west sundial which means that it does not face due south exactly but it edges westwards.

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