iï4
adopted for use in an index to the Swedish building journals.
3.5.2 In some libraries, the type of material collected may
make the use of conventional classification impracticable. The
Canadian National Air Photo Library has over three million
oblique, vertical and trimetrogon photographs, providing an aerial
view of all of Canada. This vast collection holds vital information,
not only for map-makers, but for the many people interested in the
development of Canada and its natural resources. The Library is a
unit of the Survey and Mapping Branch of the Department of
Mines and Technical Surveys in Ottawa. It maintains a complete
record of all survey photography taken by and for the Federal
Government, including a copy of each photograph and data relative
to the location and altitude of flight-lines, the flying agency, the
film, and the camera. The flight-lines of each project are indexed
on the latest published map and filed according to the national
topographic system. The specifications for photography are pre
pared by the Inter-Departmental Committee on Air Surveys. All
photos are allocated to conform to the Library's system of num
bering. Consequently, the available federal coverage of any area
can be identified quickly, and the pertinent photos are viewed
in a matter of minutes.
3.5.3 On the other hand, the 200,000 maps in the map library
of the University of California at Los Angeles are filed by the
Library of Congress Classification Scheme. To the basic classifi
cation code (area and subject) are added the name of the natural
administrative sub-division, the issuing agency, scale and date.
The classification codes and some elements of descriptive catalo
guing have been combined in such a way that they can be handled
and processed by IBM-equipment using 8o-column cards.
3.5.4 The Department of Geography at the LTniversity of
Washington have an experimental computer programme for the
retrieval of their maps. The programme was written for an IBM 7094
computer and each map reference is limited to one 8o-column card
giving information on geographic location, subject-matter, scale,
date, title, publisher and acquisition number. Location is given
throughout by map centroid or centre point expressed as latitude
and longitude to the nearest minute. The person requiring infor
mation specifies his requirements in a similar way, together with the
approximate extent of his interest, North and South, East and
West. The computer compares parameter cards with unit records
and produces the unit record satisfying all the criteria.
3.5.5 The Commission on Classification of Geographical Books
and Maps in Libraries was constituted during the International
Geographic Congress in 1952, the International Geographical Union
having recognised the great importance of the problem and thinking
it appropriate to entrust its further study to some specialists.
The commission decided to concentrate on the adjustment of the
two most widely used systemsUDC and Library of Congress. The
