El Paso herald. (El Paso, Tex.) 1901-1931, 1910-05-27
BY
Frederic
J. Haskin

I lettering, some in Topography
| each is assigned to do the par- for
| which his talents fit him. Into q sur
! face of transparent gelatine the en-
| gr&YeT traces his lines with a sharp
/ pointed instrument.
! These tracings are filled with POW
/ dered graphite, and the geIarine is then
! inverted and placed upon the copper
plate, which has previously been treated
| With a solution OF beeSwaX and alcohol.
! leaving a thin film of the beeswax on
! the plate. After the gelatine mat has
! been superimpOsed upon the copper
1 Plate, with the projections cOincident.
| the tracings are rubbed over with
| steel hUrnisher, and the markings thus
! transferred to the beeswax upon the
| copper plate. Then the engrayer IS
I ready for work on the plate Itself. This
! process is repeated until every feature
! of the map is engraved on the plate.
| The editors have carefully watched the
! whole process. so that no errors could
creep in, either of omission or commits
| sion.
! Making Copper Plates.
/ Standings and color lines are inserted
| in the copper plates by means of small
! roulette wheels. When this is finished
/ the figures showing the depth of the
/ water are engraved by the use of a pc
GldcNlNe,
1 which two msn can 90 the work of
many men The machine consists OF
/ two points on a long. movable arm
| One man places his point on the figure
on the chart TO be reproduced using
| miscrOscOpe to determine its exact posi-
/ ton, and this places the point at the
other end at the exact position on the
! copper plate at which the figure is to be
made When in position, the first man
figures n
| repeats them, and by passing a sort of
dull pointed needle through the grooves
! OF the figures which are to be made, and
which are placed on a revolving wheel,
q corresponding point cuts the figures
into the copper.
AS some sheets contain as high as 49,
900 figures, it is easy to see how need
full is the uniformity that cannot be Sc
cured by hand methods, but which IS
secured by the use of this machine.
More than a million dollars worth of
these plates are stored in non-fire-
proof building, and not a cent of insur-
ance is carried on them.
Printing is accomplished by the usual
methods Of copper plate printing.
Where more than 10000 impressions are
TO be produced, the original plate is not
used, but electrOtype copies of 1t are
made and used. For hurry orders and
for some types of charts, engraving IS
done by the phOtoIiIh ographic process
The chart to be reproduced has It's pic
ture taken, and the resultant negative
is so intensified that the chart appears
upon the glass with clear lines upon an
apaQue background From this is printed
a new chart on properly coated paper.
This paper is covered all over with a
greasy ink, and when washed off, gives
a chart in black lines. Laid face down
ward on the stone. the chart is trans
TO
chemical treatment, the stone is ready
for printing thousands of copies of II.
Keeping Up to Date.
1t is long story 10 tell Of how pilot
charts are made, how magnetic records
are kept. of how plates are altered from
time to time TO keep them down TO date
and of how more than 5000 volunteer
observers carefully maintain a lookout
for all Instructions to navigation. make
frequent reports of the conditions of
the winds, the waves, icebergs, storms,
astronomical phenomena, such as Hal
leys comet. and of everything else
that may be of value to the navigator
and his more important aid. the astron-
Omer- Bottles are turned adrift and the
whole world of seamen watch out for
them When found they silently tell the
story of the tides and the ocean cur
rents Through the information thus
gathered the whereabouts of dereIicts
is always shown. and a hundred other
dangers guarded against that might
otherwise send a mighty Lusitania to
the bottom of the sea.
One of the most interesting phases of
the work of the photographic office is
its gathering of data concerning foreign
ports Through a system of exchanges
it gets copies OF all charts issued by
other governments. From these IL
makes charts of its own. so that If there
are any errors ii is likely TO discover
them. Just as fast as the nations of the
civilized world gather data about new
harbors and new coast lines, the hydro
graphic office reprOduces IT, and makes
1t available for our navy and for the
commerce of the world Only a very
small percentage of the coast line of the
world has been accurately surveyed The
Jurisdiction of the photographic office
covers the whole earth with the exceD-
ton of the coast line offs the United
States and the waters within 20 marine
leagues thereof That is covered by the
coast and geOdetic survey.
All publications of the hydrosraphfc
office are sold at the mere cost of the
paper and ink used and of the making
of the Impressions All the cost % the
surveys and of the preparation Of the
plates is borne by the government
Tomorrow: Harvesting the Wheat
Crop.