Curry Stool

A 'Curry Stool'.

A curry stool is a type of survey mark used in peaty areas where a pillar would sink and natural rock was not available. The concrete, in the form of three arms meeting at a central point, sits on the peat and it was hoped to be a stable platform. It is contended that they were named after Corporal Curry of the Royal Engineers. However, the Yahoo post in the reference below is no longer available to view.

In the book 'Ordnance Survey: Map Makers to Britain since 1791', it states on page 120: The ingenuity of the pillar constructors and surveyors overcame most problems encountered and led to some interesting innovations such as the 'Curry Stool'. Designed by a surveyor, Mr Ernie Curry, this provided a stable triangulation station and theodolite platform in soft peat bogs. Three stout poles were driven at an angle, 120 ° apart, into the peat until they hit firm ground (sometimes nearly 20 feet down), and their protruding tops were covered and bound by a collar of concrete. The result was a triangulation station that, in diagrammatic form, looked like a vast milking stool thrust into the peat. In the middle of the concrete collar, which was large enough to take the outspread legs of the theodolite tripod, was the trig bolt. The observer stood on boards, just above the concrete, arranged so as not to disturb the theodolite.

The following Curry Stools are included in the OSGB36 list

T:UK	Station name	Order	Computed	Block
TP7467	Bink Moss	3	1962	NY71
TP7415	Camb Hill	2	1961	HU46
TP7470	Cellar Head	2	1955	NC20
TP7472	Herdship Fell	3	1962	NY71
TP7466	Iron Band	3	1962	NY71
TP7471	Killin	2	1960	NH40
TP7416	Ness of Copister	3	1961	HU46
TP7468	Rubh Aird na Sgitheich	3	1960	NM52
TP7469	Scotasay Island	3	1958	NG24

A list and a photo album of curry stools are available from T:UK.