Evening star., 1946-04-07

new method, chart original that would
take six months to produce on copper
could now be finished in as little as two
or three weeks.
The absolute accuracy demanded IN
chart making is a chief reason why
copper or the new zinc plates, rather
than paper, are used, since paper ex-
pands and contracts considerably with
changing atmospheric conditions. At sea
or in the sky, the slightest inaccuracy
may take navigator far off his course.
New Materials Speed
Mapmaking Process
So vital in wartime is the accuracy OF
charts that Hydro assigned an entire
section to correcting and bringing up to
date all the hundreds of charts affected
by changing conditions the world over.
Another technical improvement. Mr..
Medina pointed out. was the first use
in mapmaking of the plastic. vinylite.
which is familiar to the public in the
form of 'unbreakable' phonograph rec
ords.
Combining such technical improve.
ments with 24-hour, war production
plant schedule, Hydro raised its produc-
ton from million and half annually
to a total in 1914 of $4,000 900, and an
even higher rate by the end of the war.
Thousands of new nautical and aero
nautical charts were added permanently
to the index.
The necessity for close Army Navy CO.
operation in making combat maps for
war of combined operations is patent.
Giving fire support to landing forces,
the Navy had to be sure its bombardment
charts were in absolute photographic
agreement with Army maps Air sup
port, too, must be able to locate target
exactly, to avoid bombing its own troops,
Mutual points of interest must be shown
identically on all maps.
Stemming from this need a notable
advance was a standardized map for
coastal areas combining both nautical
and topographic features. designed for
use of all forces, land, sea and air, in Joint
amphibious operations. Standardized
maps of this kind were used both in the
Pacific and in Normandy. When the war
ended the Army and Navy together had
prepared a complete series of such map
charts covering the coastal areas of the
japanese Empire and China.
World Travel Trends
To Keep Hydro Active
It's war job finished, Hydro already
has turned again. to its peacetime role
as mentor of world commerce And just
as aviation broadened the scope of war
time chart making, so the prospect Of
extensive worldwide travel and trans
port enlarges Hydros postwar response
bilities.
Hydro's war-production record has at
tracted delegations of foreign chart
makers to Suitland for inspection tours.
But no better international reputation
could have been established than
through its century of service to mari
ners. Merchant ships the world over con-
tinue to benefit from Hydro's weekly
Notice to Mariners" and other naviga-
tional publications, sending in, for their
PoAl, a SOAlCAiiuouS lloW Oi OdId AOl tliS
Offices use. Soon navigators will be TAX
ing advantage of similar service on 4
comparable scale.
AS for the charts, they were already
pretty we'll known in 1923. That was the
year an earthquake destroyed most Of
the charts belonging to an infant Japa-
nese navy The United States Nays
photographic Office was the natural
place to turn. So, 20 years later. the
Navy found itself fighting an enemy
using many of its own charts