The Ordnance Survey of Great Britain. 251 
During the time that the Ordnance Surveyors were engaged in 
making their six inch map of Lancashire and Yorkshire they 
were called upon and employed to make, at the expense of the 
land owners, twenty-three plans of parishes and townships on the 
scale of twenty-six and 4 inches to one mile for tithe commuta- 
tion. 
It was even found that the plan of London, made for the 
Metropolitan Commissioners of Sewers, on the scale of sixty 
inches or five feet to one mile was inapplicable to house drainage 
within the area. 
Between 1851 and 1852 no fewer than three select committees 
and one royal commission deliberated on the scale for the survey, 
and fourteen blue books were presented to Parliament. 
The main point of the controversy was whether the six inch or 
some larger scale was best fitted for the national map. <A host of 
persons eminent in science were consulted on the subject, and a 
great diversity of opinion was found to exist, the weight of 
evidence, however, inclining by a majority of four to one, to a 
seale of from 20 to 26% inches to a mile. 
In 1853 a statistical conference held at Brussels and attended 
by twenty-six delegates from the chief States of Europe con- 
sidered the question of national maps or cadastres, and pro- 
- nounced unanimously in favor of a scale of sa; gin of nature equiv- 
alent to about 254 inches to a mile, recommending at the same 
time that the cadastre on this scale should be accompanied by a 
more general map on the scale of ;,4 95 equivalent to about six $ 
inches to a mile, and thus very nearly corresponding to the six 
inch scale of the Ordnance Survey. 
The scale finally adopted of 5,,, on which the whole of 
England has at last been surveyed, is one which corresponds with 
that adopted for the national maps and plans of the chief coun- 
tries for Europe. Lastly it possessed the incidental advantage 
that a square acre is to all practical intents represented on the 
plans by a square inch.. 
Among the many public purposes which the national map was 
expected to subserve are the following: the valuation of property 
for the equitable adjustment of taxation and assessment; the sale 
and transfer of land and the registration of title; railway and 
other civil engineering work, such as the construction of roads 
aad canals, large sanitary and drainage schemes, military engineer- - 
ing works, hydrographical, geological and mineral surveys; the 
