National Grid References

Saxton's Hampshire 1575
NGRs Simple mathematics was used to crudely superimpose the national grid on Saxton's map. The difference between the map projections used by the NGR system and used by Robert Saxton has been ignored. 'Centres' of the the old and the Ordnance Survey maps of the county were superimposed at an average position of twenty or so prominent towns; the orientations and scales were matched by averaging the directions and distances of these places from the centres on each map; it is then possible to draw the NGR from the modern map upon the image of the old. The calculations were done by a computer using a program written by MN, OLDMAPS.exe; fuller notes about the process are provided in the software notes, OLDMAPS.rul.

File SAXTON1.pts has readings of positions of recognisable places on the old map; (x,y) coordinates measured on the map.

Points
file 




@pl Alton @ngr SU717396 @xy (30.67,27.84)
@pl Andover @ngr SU365458 @xy (15.63,27.65)
@pl Basingstoke @ngr SU634527 @xy (27.18,32.27)
@pl Burghclere @ngr SU469610 @xy (19.27,33.5)
@pl Buriton @ngr SU740200 @xy (31.82,18.68)
@pl Christchurch @ngr SZ159925 @xy (9.26,3.90)
@pl Fareham @ngr SU575061 @xy (26.53,13.15)
@pl Grately @ngr SU275420 @xy (11.88,25.02)
@pl Havant @ngr SU717062 @xy (31.60,13.01)
@pl Hawkley @ngr SU746291 @xy (32.24,23.49)
@pl Kingsclere @ngr SU525586 @xy (21.61,33.85)
@pl Lymington @ngr SZ322954 @xy (15.88,6.57)
@pl Nether Wallop @ngr SU304364 @xy (13.19,23.09)
@pl Odiham @ngr SU740509 @xy (31.11,31.95)
@pl Overton @ngr SU514500 @xy (21.71,30.66)
@pl Romsey @ngr SU351212 @xy (16.88,17.45)
@pl Stockbridge @ngr SU355351 @xy (15.51,22.97)
@pl Titchfield @ngr SU541058 @xy (24.65,13.28)
@pl Whitchurch @ngr SU460478 @xy (19.29,29.99)
@pl Winchester @ngr SU478293 @xy (20.64,21.56)

@w 43.90 @h 39.54

@sc 8.33 @m 10

The results from OLDMAPS.exe are given in file: 
SAXTON1.ngr, output from OLDMAPS.exe, using SAXTON1.pt:-

Map saxton1

  Data file: saxton1.pts
Output file: saxton1.ngr


OLDMAPS

Plotting a NGR grid on an old map
version 4.1
MN: 12.2.1997



Given points

 no  place                    ngr         (x,y)

  1  Alton                    SU717396    (   30.67,   27.84)
  2  Andover                  SU365458    (   15.63,   27.65)
  3  Basingstoke              SU634527    (   27.18,   32.27)
  4  Burghclere               SU469610    (   19.27,   33.50)
  5  Buriton                  SU740200    (   31.82,   18.68)
  6  Christchurch             SZ159925    (    9.26,    3.90)
  7  Fareham                  SU575061    (   26.53,   13.15)
  8  Grately                  SU275420    (   11.88,   25.02)
  9  Havant                   SU717062    (   31.60,   13.01)
 10  Hawkley                  SU746291    (   32.24,   23.49)
 11  Kingsclere               SU525586    (   21.61,   33.85)
 12  Lymington                SZ322954    (   15.88,    6.57)
 13  Nether Wallop            SU304364    (   13.19,   23.09)
 14  Odiham                   SU740509    (   31.11,   31.95)
 15  Overton                  SU514500    (   21.71,   30.66)
 16  Romsey                   SU351212    (   16.88,   17.45)
 17  Stockbridge              SU355351    (   15.51,   22.97)
 18  Titchfield               SU541058    (   24.65,   13.28)
 19  Whitchurch               SU460478    (   19.29,   29.99)
 20  Winchester               SU478293    (   20.64,   21.56)
number of points = 20


Centroids of points


(x,y) centroid is  (   21.83,   22.49)
  NGR centroid is  SU499312
    numerical ngr  449.93 131.28


Map scale

scale =     2.26
scale =     2.45
scale =     2.27
scale =     2.64
scale =     2.48
scale =     2.30
scale =     2.51
scale =     2.42
scale =     2.44
scale =     2.35
scale =     2.34
scale =     2.54
scale =     2.68
scale =     2.15

map scale  1 to   241735
or         1 to   241000



Map heading

Map heading
NGR north on map is 7.1 degrees W of map north


Check points

 no  place                    ngr         map

  1  Alton                    SU717396    SU727414
  2  Andover                  SU365458    SU366454
  3  Basingstoke              SU634527    SU657531
  4  Burghclere               SU469610    SU470584
  5  Buriton                  SU740200    SU727191
  6  Christchurch             SZ159925    SZ142904
  7  Fareham                  SU575061    SU584074
  8  Grately                  SU275420    SU268403
  9  Havant                   SU717062    SU705056
 10  Hawkley                  SU746291    SU752305
 11  Kingsclere               SU525586    SU528585
 12  Lymington                SZ322954    SZ309948
 13  Nether Wallop            SU304364    SU293352
 14  Odiham                   SU740509    SU750511
 15  Overton                  SU514500    SU520508
 16  Romsey                   SU351212    SU365206
 17  Stockbridge              SU355351    SU349343
 18  Titchfield               SU541058    SU539083
 19  Whitchurch               SU460478    SU460500
 20  Winchester               SU478293    SU468293


Map sheet corners

 bottom left SY908838
    top left SU026786
   top right TQ079655
bottom right SZ961707


Grid lines

x positions on bottom and top edges,
y positions on left and right edges,
by which to draw lines on map

easting grid lines

Eing      bottom edge    top edge

 400          3.82          1.12
 410          7.99           3.05
 420         12.15           7.22
 430         16.32          11.39
 440         20.49          15.56
 450         24.66          19.73
 460         28.83          23.90
 470         33.00          28.07
 480         37.17          32.23
 490         41.34          36.40
 500         45.51          40.57
 510         49.67          44.74

northing grid lines

Ning      left edge      right edge
  80         1.60           3.87
  90          2.56           8.04
 100          6.73          12.21
 110         10.90          16.38
 120         15.07          20.55
 130         19.24          24.72
 140         23.41          28.89
 150         27.58          33.05
 160         31.75          37.22
 170         35.91          41.39
 180         40.08          45.56


Scale line

scale line length     8.33 cm
representing   10 miles
scale 1 to   193199


Saxton's Hampshire 1575, index grid
General index
Old Hampshire Mapped
Map HMCMS:KD1996.1