The Surveyor’s Field Book 1793
This field book is dated 1793 illustrating the survey work of Gabriel Montgomery of the Royal Manx Fencibles. He wrote the account of Lough Swilly in the Ordnance Survey Memoirs. (Refer )
The information is in manuscript form and appears to have a starting point within County Derry beginning with Farkland on page 2 , finishing with Oughtymoyle on page 87.
It shows reference compass points and measurement on each page by using 3 columns accompanied by place-names, roads, small diagram inserts, several names of tenants, page numbers with mini drawings of the tenants’ homes, contained on the horizontal lines.
Column 1 denotes the direction in relation to the coordinate points of the compass, be it north, south, east or west which are meticulously laid out.
Column 2 indicates the bearing in degrees whilst Column 3 shows an offset displaying the distance of the object on the ground from the position of the measuring instrument, suggesting that a theodolite was used.
Actually,it is difficult to determine what instrument was used for the distances, as these were written in number form only. Could the surveyor have used the Gunther’s Measuring Chain or was it by some other method?
Several local parishes are mentioned such as Cumber, Templemore, Banagher and Boveagh.
Bleach greens with mills (recorded or not recorded previously requiring initial research) are inserted with coordinates given, as are churches, graveyards, forts and other antiquities also in need of research.
On page 83 is marked “ burying place.” Obviously an old graveyard but only the coordinates can identify the location.
Spellings of the various town-lands can be compared to the modern day versions.
The surveyor has lined each page according to the essential information which only he required in order to assist him complete or design an illustrative survey which would eventually be converted into map form. It appeared to be a painstaking journey through part of the Counties Donegal and Derry.
Of course, a real challenge would be to use all the field book information by endeavouring to create, where possible, a unique map of the registered compass points showing distance on a suitable scale.
A map, from an original rare field book of this type, would require the specific expertise of a modern day professional. Enquiries to some of the repositories here in Ireland have revealed that there are few similar works available for comparison.
However the challenge is still available.
This is a very rare surveyor’s field book in manuscript with numerous inserts which certainly need some investigation.