The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1895-09-08

The Process In Laborious and Costly
and Demands Infinite Care.

HOW MAPS ARE MADE.
The Process II Laborious and Costly
and Demands Infinite Care.
Golden Days.
All maps, large and small. are practically
produced in the same way, and we can
best explain the process of map-making by
describing the various stages tnrougn
school or reference atlas. pass.
First of all. the geographer decides what
Indicated by the publisher or author. the
extent of country to be shown, the amount
Of information required and the like.
draughtsman proceeds to prepare the
drawing. He determines the projection
and scale npo which the area TO be IN
cluded in the map can be best shown. This
projection is drawn within the specified
limits and is generally undivided into a
material used in its compilation. be II an
engineer survey sheet, a photographic chart
or a travellers manuscript map, IS SIM
ilarly squared" If minute accuracy is de-
The outline-that is the coast line and
rivers, is then carefully drawn In pencil.
to an engraver, who places a tracing OF IL
face downward on a finely polished copper
plate that has been previously, coated with
outline on the paper is transferred to the
waxed surface of the plate, OF course in the
reverse.
worked from the elbow and not like a pen
or pencil, from the wrist-the engraver cuts
plate. AS he advances, proofs are pulled
for the purpose OF revision, and when the
outline lis finished and finally passed, a
proceeds to write In the names selected
by the g~eographer or indicated by the au-
thor or publisher.
sizes, according to the import and relative
value" of the names. Some are sioping,
others upright, some in italics. Others in
given to a letter engraver. who cuts the
names in reversion on the outside plate.
exercising the greatest care not to make
the slightest mistake, as a wrong letter or
name entails q great deal more trouble to
correct than to engrave at first.
been wrongly engraved and has to be put
right. To make the requisite alteration
1t is necessary, first Of all, to .gouge out
pers to mark its exact position on the back
Of the plate, which is then laid face down.
ward on a small anvil of polished steel.
is then forced up from the back with ham
mer and punch. The name is regraved
correctly and the adjoining names and out
line damaged in the process OF erasure or
punching are recut.
When the names are all cut a letter proof
is taken = and and n caGsfq II ,.k reyis snd ON w tbis
mountains and hills in sepia.
These the hill ens S r iss. f Tgs riuss oy with bn
a process called etching, which Is thus
done: The plate is coated with a compost
ton called etching ground. on which the
tops of the hills are traced.
The different attitudes are shown by
varying the strength Of the lines, which is
effected by allowing the acid used to bite"
them in to remain on the plate for a lon
ger or shorter time until the requisite col
orr or shade is obtained.
The printer takes an impression-tech-
nically known as a TRANSCRIPTION the
plate on specially prepared paper, coated
with a preparation easily Influenced by
ceptible to heat.
After being cleaned and etched with
nitric, acid and gum arabic the stone of
who fixes 1t securely on the photographic
printing machines. and from it the map is
printed first of all in black; The proper
ticns of the mar colored yellow, pink and
blue are separately transferred and
etched on other photographic stones, and
printed one after the other, in the order
Each map or sheets of maps is thus print
ed once for the black and once for each
color. except in the case of certain sec
which are produced by printing one of the
primary colors over another-thus. red or
pink over blue gives purple; blue over yell
low gives green.
Many of the cheaper maps, both large and
small, are not engraved on copper plate or
zinc. but are written on the lithographic
stone, from which the black is printed or
transferred to another stone for printing
from. On such maps the hills are drawn in
chalk.
Political maps are colored to show clearly
the limits of counties, or other political di-
visions, while physical maps of counties and
continents are often colored geographically
that is, the different attitudes are shown
+ b. different colors. or by different tints of
the same color. !
Contour maps of the sea. lakes, etc, gen.
orally show the varying depths by various
shades of blue. The relief of the lane is
usually show by coloring the lower lands
green, the midlands light brown or yellow
and the uplands dark brown.
Sometimes. when the relief of both the
scaled and the land is shown on the same
map, as many as fifty contour lines are
drawn and the intervening spaces different
ly colored or tinted. thus indicating in a
graphic and most unmistakable way the
alteration Of level from the lowest depths
of the sea to the Hottest heights on land.
Quite a number of the smaller maps are
printed at the same time on one sheet. The
sheets are folded and the edges cut for an
| ordinary atlas. or are cut into single sheets
for separate sale, for mounting on guards
or for insertion in books.
Maps that measure 22x30 inches are print
ed one at a time; larger wall or school,
room maps are printed in sections and
Joined together when being mounted on
cloth. After being mounted they are var
nished and then nailed to rollers.
Map making, then. even when the ma
ter.al has been supplied by slSfllful survey
borious and costly matter. The three es-
sentia1 processes. as We have seen, are the
drawing, the engraving and the printing,
and a good map must necessarily have
been well drawn, carefully engraved and
finely printed