In the organization and equipment of the Ordnance Survey, as it exists to-day, no pains are spared to secure the utmost precision and economy in its methods of field work and publication.
After more than a century of development and the completion of the cadastral map, let it not be supposed that its mission is at an end, for it is proposed to make a complete revision of all the cadastral work at least once every twenty years.
This is rendered necessary by the constant changes in property boundaries, and the growth of population—which may be gathered from the fact that the city of London increases in population at the rate of about 50,000 a year, and that eighty or more miles of new streets are added in the same time.
II.
The Ordnance Survey of Great Britain as it exists to-day is a remarkable Publishing Bureau, from whose presses are given the most elaborate and accurate series of maps which any country possesses.
Maps not alone confined to the representation of the physical features of the country, but containing every detail of interest or value for civil or military purposes.
It has justly gained the commendation of the French that it is "a work without precedent, and should be taken as a model by all civilized nations."
The principal scales of publication adopted by the Ordnance Survey are: (1) A general map on the scale of one mile to one inch. (2) County plans on the scale of six inches to one mile. (3) Cadastral or Parish plans for the whole country on the scale of 1/2500 or about 251/3 inches to one mile, on which one square inch on the plan represents an area of one acre. (4) For towns of over 4000 inhabitants a scale of 1/500 of actual length on the ground or 1056/100 feet to one mile.
On the latter scale the city of London with its environs could not be well shown on a sheet of paper less than 300 feet long by 200 wide.
When the facts are taken into consideration, that the Ordnance Survey is a cadastral one, in other words, that one of its many objects is the measurement and definition of all existing boundaries, political, municipal, parochial or private, and a survey and valuation of property for assessments, that its maps are accepted in courts of law as authoritative on such questions, then the problem of the scales of publication is the most important one to be considered.