Full register
Every entry, by section
Twenty-six decisions taken between the ground and the sheet, each recorded with the scale and the method it was taken at.
Projections
Section page- 001Where a projection is chosen before the ground is knownThe sheet's projection is often fixed by the series, not by the terrain on it. What that costs at the edges.3 min
- 002What conformal spendsAngles preserved, area sacrificed. Where the sacrifice becomes visible on a sheet you would actually carry.2 min
- 003Equal area and shapeThe opposite bargain, and why it is unpopular with anyone navigating.2 min
- 004The grid is not the graticuleTwo sets of lines on the same sheet meaning different things, and the angle between them.2 min
- 005Zones and seamsWhere two zones meet, coordinates do not simply continue. What happens at the join.2 min
Relief
Section page- 006The interval decides what counts as a hillA forty-foot interval and a ten-foot interval over the same ground produce different landscapes on paper.3 min
- 007LevellingHeight is carried across country one instrument setup at a time, and every setup adds a little error.2 min
- 008The datum a height is counted fromEvery elevation is relative to a surface somebody chose. Readjust the network and every number moves.2 min
- 009Stereo compilationTwo overlapping photographs and one operator's eye. How relief got drawn before laser.3 min
- 010Form linesContours drawn by judgement rather than measurement, and how to spot them.2 min
Hydrography
Section page- 011One river, two official coursesA channel surveyed on the ground and a channel compiled from air photographs do not agree, and neither office will call the other wrong. The register records the separation and leaves both centrelines standing.6 min
- 012Blue lines that only run after rainIntermittent channels, the dashed convention, and how much of the network is conditional.2 min
- 013The gaugeOne point on the reach where both surveys agree, because it is the point both are tied to.2 min
- 014Mean stageA river's edge is drawn at a level it is at only some of the time.2 min
- 015A cut-off bendThe old channel stays legible in the crop long after the water has gone.2 min
Boundaries
Section page- 016A census tract is drawn around a numberStatistical geography starts from a target population and finds lines to fit it, which is the reverse of how it reads.3 min
- 017Borrowed featuresBoundaries follow rivers, roads and ridges because those were already surveyed — and inherit their errors.2 min
- 018When the feature movesA boundary tied to a river that has since shifted. Which one wins depends on the wording.2 min
- 019Block levelThe smallest published unit, and why it is published at all.2 min
Names
Section page- 020Two spellings, one printedThe names register holds variants; the sheet has room for one. What the choice commits the map to.4 min
- 021Who decidesThe board, the local usage, and the long gap between them.2 min
- 022The variant held in noteNot printed, not discarded — kept in the record against the day it is needed.2 min
Canopy
Section page- 023Bare earth under closed canopyAirborne laser, last return, and the relict field systems that turned up under forest nobody had surveyed.3 min
- 024Last returnOne pulse, several echoes. Which echo is the ground and how the classifier decides.2 min
- 025The half-metre gridResolution fine enough to see a plough furrow, and the storage that implies.2 min
- 026What the laser missesDense evergreen, standing water, and steep ground facing away from the flight line.2 min