250 National Geographic Magazine. 
The townland was the lowest unit of taxation for country pur- 
poses, of an average size of 200 or 300 acres, and originally the 
map was to be simply a topographic map, containing the bound- 
aries of the townlands, the roads, the streams and the houses, 
with a view to the valuation of Ireland for the county assessment. 
The six inch was considered to be the smallest scale that could 
be available for that purpose. 
There was no intention in the original Irish survey to insert the 
fields, but when the valuation began, it was found by the valua- 
tors that additional minuteness was necessary to enable them to 
subdivide the townlands into the qualities of lands of which they 
consisted, and more especially that the boundary between the 
cultivated and uncultivated portions ought to be inserted on the 
maps with great accuracy. 
This rendered necessary a very extensive revision which was 
undertaken in 1830, and it became a survey by fields instead of 
townlands. 
This was clearly a.wide and most important departure from the 
original intention of the six inch survey in Ireland, and it is not 
to be doubted that General Colby, who would not trust to paper 
measurements for the areas of entire townlands, would have 
adopted. at the very outset, for his manuscript plans of these 
minute subdivisions, a scale much larger than that of six inches 
to one mile. 
The engraving of the six inch survey appears to have resulted 
from a demand for six copies of one sheet for valuation purposes 
when it was found that it would be as cheap to engrave it as to 
make that number of copies. 
So valuable did the six inch map of Ireland prove for many 
purposes over and above that for which it had been originally 
designed, that, in 1840, when the Irish survey was completed, and 
that of England resumed, the Government gave their consent to 
the adoption of the same scale for the unsurveyed parts of Great 
Britain. 
By 1851, Yorkshire, Lancashire, the Isle of Lewis, and several 
counties in the south of Scotland were finished on the six inch 
scale. 
Then began that long controversy which has been well termed 
the “battle of the scales” and which for eleven or twelve years 
retarded the progress of the survey and led to a large waste of 
public money. 
