Line Style, Abbreviations & Modern Symbols
Much information could be conveyed through line types. A solid
line indicated a solid wall. A break in a line showed doorways
and other passages. Additionally, dashed lines could indicate some
aspect of wall construction or the presence of a mansard roof.
Extending solid lines beyond the edge of a building was a technique
for indicating how high above the roof fire walls were built. When
interpreting any fire insurance map, researchers should take care
to consult the legend for that particular edition to ensure the
correct interpretation of line symbology.
Fire insurance maps often relied on abbreviations to convey the
type of activity that took place in a structure, since that information
had some bearing on the likelihood of fires. The most common abbreviations
are as follows: "D" or "Dwg" for a dwelling, "F" for
a flat or apartment, "S" for a store, "Sal" for
a saloon. Other abbreviations added more information about a structure:
numerals were used to indicate the number of stories in a building,
and the letter "B" indicated the presence of a basement.
These could be combined, so that "2B," for instance,
indicates that a building has two stories and a basement. Multiple
symbols for a single structure could reflect the use or nature
of different parts of a building; hence a two-story building with
a basement might be marked "2B" for the main portion
of the structure while an addition on the front had the number "1" by
itself to indicate a single story.
In some instances, symbols and abbreviations were combined with
text to describe a specific use. These can be frequently difficult
to interpret because they are run together; the symbols for store
and basement, for instance, can be combined in the form SinB, representing
the phrase "store in basement."
Modern Symbols for Fire Insurance Maps
The symbolization used on fire insurance maps evolved over time
as a result of such factors as the consolidation of the industry
under the control of the Sanborn Map Company, the development and
improvements of building codes, the development of larger and taller
buildings that required notation of special features, and the maturation
of this form of cartographic endeavor. To aid researchers in using
these maps, a series of keys or legends have been reproduced from
reference manuals that the Sanborn Map Company produced for its
employees. Researchers, should not rely solely on the extensive
legends reproduced here, however, the legends published in the
atlases and on the small editions issued as loose sheets represent
the use of symbols at the time the map was made.