decompressions. At this point the images of the charts were in a format that could be
manipulated using software already at hand, Adobe Photoshop.
Not all of the images used in the project were decompressed at this time. Other
relevant files were discovered after this initial run. The above process was repeated for
each new group of .sids that was to be included in the project.
Choosing What to Clip
The next decision to make was which chart components to compare in order to
best understand the changes that were made to their design and content. This decision
would inform choices about which sections of each chart edition should be clipped out
and assembled into displays of like sections to ease comparison.
Several sources provided inspiration in deciding what chart features to compare.
Morrison et al. in Charting the Chesapeake (1990) offer considerable textual comparison
of chart features, albeit in a non-academic way. Specifically noted in this work are the
design of hydrography (stippling changed to tinting, contour lines) as well as its content
(current arrows, location of channels), the content of topography (“buildings, woods,
roads, cropland, docks, towers, and other features, (88)”), and the movement of
information on and off the charts. Textual notes on navigation were moved to the Coast
Pilot, also, published by the C&GS, for example.
Fillmore’s work The Chartmakers: The history of nautical surveying in Canada
(1983) is another popularizing work that includes some chart dissection. It mentions the
standardized symbology on contemporary Canadian nautical charts such as navigational
aids, hydrography (deepwater channels, hazards, depths by contour lines), place names,
and cultural features (roads, streets, buildings, railways).
In tracing the history of engraving at the U.S. Geological Survey, Phillips (1997)
provides some discussion of map design that is relevant to this project. Representation of
topography was a particularly important decision for the USGS, especially the
establishment of standard symbols and lettering, which the agency did in 1885.
Standardization of chart symbols, including topography, was something the C&GS also
did. While some guidance was given early on regarding representation, the first set of
standard symbols published by the C&GS did not come out until 1860, 16 years after the
first charts were published (Allen 1998; U.S. Treasury Department et al. 1861).
Robinson directs much of his discussion in “The Evolution of the English nautical
chart” (1952) to changes in technology that led to more accurate charts over time. His
temporal comparison is not systematic, however—for each snapshot in time he focuses
on one or two changes that may or may not have been discussed previously in the article.
His work is also more of a general history than a cartographic critique. Of interest to this
thesis is the way he includes figures showing side-by-side comparison of charts to
facilitate reader understanding.
Magee’s 1971 article on the changes to the design of British Admiralty nautical
charts includes several paragraphs on the choice of fonts as well as a short history of the
addition of more and deeper depth contours as the draft of ships increased (7-10). His is a
general discussion that does not make a methodical comparison of multiple editions of
An article from 1974 also looks at the new Admiralty charts (Kitching 1974). It is
a critique of the design rather than an introduction. The author describes the following
chart components for a single sheet at a single point in time:
• Sheet size
• Chart division and ordering (geographic
• “Graticule of meridians and parallels”
• Compass rose w/ magnetic information
• “Titling and marginal information”
o Main title and sub title
o Dates of surveys
o Representative fraction
o Height, depth, and projection
o Source and date of publication
o Notes of revisions and corrections
o Conversion tables for feet, meters,
o Sheet number
o Notes on navigation and reference to
• Method of topographic relief
• Discussion of cultural symbols
• Hydrographic features:
o Depth, type of representation
o Bottom characteristics
o Navigation hazards like drying rocks
o Tide and current information
• Representation of coastline
• Navigational aid symbols
More like this thesis is the first half of Morris’ “Paper Chart to Digital Chart:
Possibilities and problems (1986).” The author discusses three different British charts
from five time periods:
1. Houat Island, 1800 [the first chart published by the office of the Hydrographer of
2. Approaches to Plymouth, 1859
3. Approaches to Plymouth, 1916
4. Approaches to Plymouth, 1964
5. Approaches to Plymouth, 1986
6. Chart 1610 (Dover Strait and the Southern North Sea), current (1986)
The comparison of the charts discussed:
• Degree of detail
• Specifics of topography, hydrography
• Extra text (sailing directions, warnings, radio and pilot information, etc)
• Statements on surveys
• Chart date and survey date
• “Rules” – designated areas, and regulations
• Signal lights
From these examples and also from the discussion of chart components by C&GS
authors at various times, the following list of chart items was selected for comparison in
• Production and Printing
o Copperplate engraving vs scribing
on glass, plastics
o Copperplate printing vs
o Design and role of bathymetric
o Bottom surface description
o Shoal water representation
o Relative density of soundings,
channels vs elsewhere
o Navigation aid symbols (buoys,
o Compass rose and magnetic
o Topographic information
o Cultural information
o Notes and explanatory information
• Design and organization:
o Numbering system
o Neatline format
o Title and Short Title
o Statement of Responsibility format
o Movement of information from
inside to outside of neatline
o Standardization of chart marginalia
The chart components selected for capture and analysis were chosen for different
• Color is used as an important marker of changes in printing technology.
Lithographic printing allowed for multiple-plate color separations. This increased
the amount of color that could be added to charts compared to hand-coloring
copper-plate prints. The expanded scope in the use of color offered new options
• The representation of shoal water is used as an example of changes in
engraving, printing and overall chart design, and is also tied to ship propulsion
• The density of soundings and delineation of channels were chosen because
changes in ship-building, in particular the advent of mechanical propulsion and
the subsequent increases in ship draft, size, speed and steerability, prompted
changes to the way hydrographic surveys were performed as well as changing the
focus of the information collected about the sea bottom. It is also used as an
example of advancements in the technology of hydrographic surveying.
• Aids to navigation are included to demonstrate increasing standardization of
chart elements, as well as changes to symbolization from several causes, from the
changing needs of ship captains to increasing international contact and
cooperation among mapping and charting agencies.
• The compass rose, sometimes called compass card, was chosen as another
example of the application of mechanical engraving aids. The compass also is an
indicator of progress in the understanding of terrestrial magnetism. The C&GS
was one of the most important researchers into the earth’s magnetic field, in
particular the change in magnetic variation at different locations over time.
• Representation of topography and cultural features are included to show how
the idea of what constitutes a nautical chart has evolved. It is also a proxy for
advances in surveying technology.
• Chart numbers are included to illustrate the adoption of standards and systems
within the operation of the survey. As a large bureaucracy, management methods
were developed and strengthened over time, and as internal systems became
organized, so were the charts. Several different systems of chart organization
were in place over the time period of this study.
• Typography had attention paid to it in waves over the years, and lettering was
performed using several different methods and technologies.
• The neatline is used as an example of changes in the engraving technology used
by the C&GS. Over time the Engraving Division increasingly relied on
mechanical aids to help engrave repetitive or simple portions of chart. Engraving
the neatline was among the first tasks so assisted. It is also a proxy for
standardization of chart elements.
• Title, short title, and statement of responsibility are included as further
examples illustrating the adoption of standards and systems within the agency, as
well as for engraving methodology, and for the standardization of chart elements.
Together, these all contribute to an understanding of the pressures, whether internal or
external to the C&GS, leading to the dramatic changes in the agency’s published charts
during the century examined here.
Having decided the intellectual component of the comparisons, practical
considerations came up. Making visual comparisons requires a reasonable degree of
proximity for the items being compared, and spatial proximity is preferred to temporal
proximity for such comparisons. The limitations of screen resolution make spatial
proximity of comparable elements of multiple large digital files impractical, and temporal
proximity (flipping between images) for such large files is rendered infeasible due to
limitations in computer memory—the .tiff files of the charts total over 30 GB of data.
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Likewise, the physical difficulty of shuffling several dozen large-format printouts of the
digitally-sourced charts would preclude acceptable spatial and temporal proximity.
In the face of this, it was decided that the most practical way to achieve proximity
and to ease comparisons would be to create layouts containing digital clippings from each
chart of only the elements of highest relevance for making desired comparisons. Small
sections of charts, collected in close spatial proximity, would make comparisons practical
either on-screen or in a limited number of large-format printouts.
From the list of chart items selected for comparison (above) a plan was prepared
detailing exactly which sections of the charts contain the content to be compared. These
common sections could then be compiled into layouts. Each clipping would be copied out
into its own file, and then assembled into a layout with all of the other clippings of the
same character, one (or two) from each relevant chart. Below is the list of sections
selected for compilation. A brief explanation tying the chart sections to the components
to be compared is included with each entry, where necessary:
1. Upper left corner: neatline, numbering system
2. Title, including logo and representative fraction
3. One compass rose, preferably one without much topography/hydrography inside:
compass rose, magnetic declination
4. One section of shoal water
5. One section of a channel: bottom surface description, sounding density
6. One section of deeper soundings: bottom surface description, sounding density
7. One section of urban topography: cultural features
8. One section of non-urban topography: topographic information
9. Examples of color, if present
10. A representative section of notes (may be one or more, depending): notes and
11. A representation of aids to navigation
12. Bottom center: movement of information from inside neatline to outside
13. Lower left: numbering system, chart standardization
14. Lower right: titling, numbering system, chart standardization, representative
15. Full charts: reference
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Copy, Save, and Assemble
With the task of deciding what to examine complete, the next task was to prepare
the collections of clippings that would aid in performing the comparisons.
The first step was to create a directory structure in which to organize the files. The
six charts each had from five to eleven editions totaling 40 separate edition dates (some
charts had multiple editions of the same year). With around 14 files copied out from each
original, the 560 resulting files would be difficult to manage without a pre-defined
Six subdirectories were made within a primary
directory, one for each
of the six charts. Each chart edition, as shown in Table 3, then had a subdirectory created
for it. The result was 40 subdirectories with paths looking like this example:
To create the saved sections of a chart edition, the .tiff file was opened in
Photoshop. This could take as long as five minutes for each of the largest files. Four of
the fourteen clips did not require any decision-making—Upper Left, Lower Left, Lower
Right, and Bottom Center were pre-decided and did not have to be sought out. Two other
clips were obvious (Title, and Compass Rose) but had varied locations. The other seven
(Shoal Water, Channel, Deep Water, Urban Topography, Non-urban Topography, Notes,
Color, and Aids to Navigation) were more abstract and took longer to find and complete.
Decisions had to be made for each chart as to which section of a symbol (for example,
shoal water) out of the total area of that symbol on the chart best shows how that chart
symbol was designed and printed. A conscious effort was made to select areas common
to all editions of a chart and to clip the same area from all the editions. Doing so aids in
identifying changes to that location and to the symbols used there.
Notes were taken for each edition while working with them in an effort to capture
other information, especially oddities and inconsistencies, of which there were many.
One example was that two charts (NY40 1902 and E1200 1881) were scans of only half a
chart—the top or bottom sheet of a two-sheet chart for which a copy of the other half
could not be found. A bit stranger was SF40 1947A. The scan was missing about two
inches on both the left and right sides. All these instances meant that one or more of the
planned clips could not be made. Unfortunately, the small-scale charts (E1200 and
W1200) had almost no representation of anything that could be termed a ‘channel.’ The
scale does not permit representation of such a small feature, and mariners should not use
a Sailing Chart to navigate inshore channels. The Channel clip is therefore mostly absent
for these charts.
Aside from these few examples, the work went smoothly. The procedure for
saving each clip into its own file was as follows:
1. Using the Select tool in Photoshop, draw a rectangle defining the area of the
image to be saved.
2. Copy the selected area to the Clipboard (
3. Create a new document (
), naming it following a naming convention.
4. Paste the contents of the Clipboard into the new file (
5. Save the new file (
) to the appropriate subdirectory.
6. Close the new file (
Once files of all the editions had all been processed, the next step was to organize
the clips into layouts to facilitate comparison. The displays were created in Adobe
InDesign, a desktop publishing program. InDesign is similar to software such as Quark
and Microsoft Publisher. It specializes in bringing together in a single document multiple
files in multiple formats in order to print complicated page layouts. The advantage of
using a page layout program over a word processing program for this task is its greater
control over placement of images, and the fact that files imported into a page are, by
default, linked rather than embedded. Linking means that the program does not make a
copy of the placed file inside the layout file. Rather, it merely displays the file, and all
that is saved in the layout document is a reference to the linked file. This makes for a
smaller file size for the layout, which is quicker to open and easier to work with.
To begin, a layout template was built. The page size was set at 36 inches wide by
72 inches tall—a large layout was deemed optimal for displaying the high-resolution
.tiffs in case they are ever printed. A six-column by nine-row grid was drawn—columns
for the six charts, rows for the nine time periods, which is the same layout as Table 3.
Text blocks were inserted to label the rows and columns, and each of the edition years
shown in Table 3 were named by a text block placed appropriately.
At this point the first display was saved as
. All of the clips
of the upper left corner, one from each of the 40 editions, were placed in the page layout
in or near the proper cell for its chart and time period. They were sized to be as large as
possible, and arranged to avoid interfering with any of the other images on the page.
Fourteen other displays were then created, based on the first. Because the files
appearing in the image frames in each InDesign document are merely linked, not
embedded, it is simple to change which image is displayed. The program has a Links
palette just for maintaining links to outside files. Select an object (in this case an image
frame) in the list of links and the file displayed in that image frame can be changed to a
different one by browsing the directory structure and selecting a new file. Changing the
source of each image frame from one image to another took very little time.
After changing the links, it was necessary to manipulate the frames to fit each
new source image. The command “Fit Frame to Content” (
) changes the
shape and size of the frame to reflect the actual aspect ratio and resolution of the source
file. After fitting, most all of the frames would then have to be resized manually to once
again fit properly with the images around it.
Most of the 15 displays have instances where more than one clip was saved for a
single edition. This was most prevalent for the Notes display, which was more loosely
defined than the others. All efforts were made to fit in any additional clips deemed
relevant. This was helped by the previously mentioned fact that some of the scans were
missing parts and therefore certain of the clips could not be made, leaving space open in
the displays where the missing image would have gone.
When the 15 displays were finished, each was converted to a .pdf. Doing so
makes the files viewable on computers that do not have Adobe InDesign installed. It is
assumed that .pdf files will be able to be read by more computers, and for a longer time,
than the original .indd files. These .pdfs have been copied to a CD-ROM that can be
found in an envelope at the back of this document. An 11-inch by 17-inch print of each
layout is also included in Appendix D.
With the displays complete, the pieces were in place to examine the history of
design changes for the first century of U.S. Coast and Geodetic Survey charts.
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