Catalogue description Ordnance Survey, MINOR CONTROL POINT ALBUMS-

The collection contains all the Minor Control Point albums for the London Borough of Lambeth and includes some areas that were in the Metropolitan Borough of Wandsworth before the new Boroughs were created in 1965.

These albums refer to revision points, which were used as starting points when revising published mapping and were much used in the 1940's and 1950's. These points were shown on the Ordnance Survey 1:1,250 and 1:2,500 scale maps-initially using a lollipop symbol and later on using the 'rp' symbol.However,changing survey methods rendered them largely obsolete and they were replaced in 1980 by permament traverse stations,which are marked by a rivet,pipehead or similar object and fulfil the same function as revision points. The control points thus represent the framework of previously fixed points used to determine the position,scale and orientation of the detail of the map

DESCRIPTION OF A TYPICAL MINOR CONTROL POINT ALBUM

Each folder bears the TQ number for the relevant Ordnance Survey map and the contents are as follows:

-Queries and Amendments to Minor Control Point data(O.S.480)

- Table of all Minor Control Point numbers for each TQ sheet number-along with their grid references in metres East and North

-One page showing control point numbers destroyed and the date when they were destroyed-along with any details of errors or omission.

-Replacing minor control points requires a separate form from queries about and amendments to minor control data.

-A list of National Grid co-ordinates of revision points falling within each square kilometre-including any revision points, which have been destroyed

- Series of location plans to show where each control point is situated-including roadnames and buildings and other landmarks relevant to the area and measurements where they are useful.Destroyed controlpoints and street renamings are also shown.

LIST OF TQ SHEET NUMBERS PLUS CORRESPONDING LAMBETH SHEET NUMBERS

TQ 2869-TQ 2876(Lambeth OS sheet numbers 1 to 9)

TQ 2969-TQ 2977(Lambeth OS sheet numbers 10 to 41)

TQ 3069-TQ 3080(Lambeth OS sheet numbers 42 to 86)

TQ 3170-TQ 3180 (Lambeth Sheet Numbers 87 to 126)

TQ 3270-TQ 3277 (Lambeth Sheet Numbers 127 to 150)

TQ 3370-TQ 3371.(Lambeth Sheet Numbers 151 to 154)

The TQ sheet numbers are the National Ordnance Survey References used for the 1/1250 and 1/2500 map series and each TQ sheet covers 4 of the Lambeth 1/1250 sheet numbers-arranged in a square 2 sheets long and 2 sheets wide.

To order up a given file,the user must quote the corresponding TQ number and if they do not know this,then they must look up the road or area they want on the1/1250 key map in the searchroom map cabinet and determine the corresponding TQ number from that.

Ordnance Survey

Acc No. 1990/1

Depositor: Ordnance Survey

Date: 1/1991

Condition: Donation