Information:
Mathematical data information is used with
cartographic materials to assist in determining scale,
projection, and could contain coordinates and equinox.
In the MARC record this information is entered into
the 255 tag and is a required field for cartographic
material. Cartographic materials will include such
items as maps, atlases, and globes or other items that
represent the whole or part of the earth or any
celestial body.
Chapter 3 of AACR2 covers creation of cartographic
materials and Rule 3.3 deals specifically with the
mathematical data area of the record. The statement of
scale (Rule 3.3B) is given as a representative
fraction expressed as a ratio (1:x). The statement of
projection (Rule 3.3C) is entered if it appears on the
item. Statement of coordinates and equinox is entered
if available (Rule 3.3D), entry of this information is
optional.
RDA guideline 7.25.1 gives basic instructions on recording
scale. Scale is recorded as a representative fraction
expressed as a ratio (7.25.1.3). Projection is recorded if
considered important for identification (7.26.1.3). Guidelines
on recording the coordinates of cartographic content
(longitude and latitude) are given in (7.4.1.3). When
coordinates for celestial cartographic content are recorded,
a statement of equinox is also recorded as a year (7.5.1.3).
Subfield a will contain the statement of scale as it
appears on the item. Begin the subfield with the word
Scale followed by the scale ratio. When calculating
the scale information that does not appear on the
item, enter the resulting ratio in brackets. When no
information on the scale is given, enter Scale not
given in subfield a.
Subfield b contains the entire statement of projection
found on the item. Use the abbreviation of proj. for
projection.
Subfield c contains the statement of coordinates in
the order of the westernmost longitude, easternmost
longitude, northernmost latitude, and southernmost
latitude. This information is always enclosed in
parentheses with the longitude and latitude
information separated by a slash. Each longitude
statement and each latitude statement is separated by
two hyphens.
Subfields d and e are used with celestial charts.
Information on right ascension (RA), declination
(Decl.), or zones goes into subfield d. The
information on right ascension and declination is
separated by a slash. When two right ascensions are
found, give both separated by the word "to".
Subfield e contains the equinox as a year preceded by
eq.
Indicators
First Undefined
blank Undefined
Second Undefined
blank Undefined
Subfields
a Statement of scale (NR)
b Statement of projection (NR)
c Statement of coordinates (NR)
d Statement of zone (NR)
e Statement of equinox (NR)
Punctuation
Subfields d and e are separated by a space semicolon.
Data in subfields c, d, and e is enclosed in
parenthesis.
The tag ends in a period.
Examples:
255 _aScale 1:7,500,000.
255 _aScale not given.
255 _aScale varies.
255 _aScale [ca. 1:13,835,000]. 1 cm. = 138
km. 1 in. = 218 miles ;
_bChamberlin trimetric proj.
255 _a1:250,000
_c(E 32(30'--E34(30'/N35(30'--N 35(00').
255 _aScale 88 mm per 1(
_d(RA 16 hr./Decl. +30( ;
_eeq. 1973).
255 _aScales vary
_d(Zones +90( to +81( to 63(, -81( to 98( ;
_eeq. 1950).
255 _aScales vary
_e(eq. 1986).
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