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
|TP7416||Ness of Copister||3||1961||HU46|
|TP7468||Rubh Aird na Sgitheich||3||1960||NM52|
A list and a photo album of curry stools are available from T:UK.
- ↑ Richard Short via Jon Rouse - Trigonomy post https://groups.yahoo.com/neo/groups/trigonomy/conversations/messages/1806
- ↑ https://www.ordnancesurvey.co.uk/legacy/docs/gps/CompleteTrigArchive.zip