The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1853-11-12

besn revived by using much perfect Instrument
be said to bs trial. with fair prospect Of better
success.
The contour lines are either reduced 10 pencil and made
the sude for the craftsman in hachureing the hills by
short perpendicular pen strokes, the
duced in hk, and the engraver puts In tho achures
pngravers The best reductions have almost mcrosco-
pic accuracy of detail while In point Of nish and style
they are rarely much INFERIOR aud sometimes SUPERIOR TO
the engraving They executed in great under
glass 10 reducing the photography only
limited selection Of the soundings actually made ia
tanned, the choice beir made with view - presenting
the important Characterization of the ocean bottom.
Curves Of depth carefully made out and
guides Cor the engrvers in ding the bottom slopes
The wing depai nent has much work to do in pre-
pairing sketches for the annual reports and in answering
calls for information by traced copies.
Next in order comes the Engraving department. In
this the finished reductions aud sketches of the dra Eiag
transferred By eDgravers to ints
copper plates all the lettering Of sailing directions
names titles notes. tide tables &c. are executed from
and the views Of headlar ds an harbor en-
trs noes engraved etched from the orig aals.
Tbs Of the copper plate sngavers few and
simple though the attainment OF skill in their re-
quires long practice The engraver first traces the out
lines and details of bis wok transparent of fish
glue Having flashed delicate film of over the sur
face of his copper plate he his tracing in its
correct position the 6lm and transfers the
black lines Of his tracing to the plate The lines oens
thus printed on the wax he follows them with
tracing point and lightly cuts them into the copper,
10 afford sufficient guidance for the etaled strokes
Of the grayer Most OF tae office engraving is executed
is employed for of the views and s.me what too
for pnosssnce Topography Ia this process the
grayer lays bis ground OF wax and then with needle
point DAVIS the desired lines through the coating.
When b. has completed this drawing he encloses his
graved in DYKE and pours 1t acid so!u
ton whchis suffered for carefully regulated interval,
10 est into The copper along the lines of drawing the
surface being elsewhere protected by the coating
The lettering is all done with the graver in pure English
letters and Coast Survey letter specimens par
hap superior in beauty of execution any other letter
engraving done in this country When
necessary the method pactised is scrape with
napier per the field of erasuIe and then
lay this followed spot, face 6ownwards small anvil
while by hammering the back the plane face Is
stored or beaten up Thus the plate, when done has
polished plane copper surface except the engraved lines
which cut in like little valleys ravines this cop
per prairie The rugged burr of copper left along the
edge OF these lines by the graver ground away by ,o
ing the face OF the plate for time with tampon Of
charcoal OF all lines and letters require to be
reversed on the plates.
Next to the wing the process eectroyping
having for its object to uply copies Of
the most elaborse plates which sometimes is sppkd
three years work of first class engravers exactly
jury 10 the original This art has been atty promoted
by he highly successful abors and devices of Mr.. G.
Mahot the pis in the Coast Survey Uce and
the copying OF plates has reached decidedly
higher perfection in his hands than in any
other known place Or circumstances in the
may be in the Coast Survey electrotype plates
hibted at the Crystal Palace The process simply this:
The original plate Is syered washed in alcoholic
light 1t ia then suspended in solution Of sulphate Of
copper parallel to- and about inch from another plate
OF rolled copper current from powerful battery of
quantity is then passed that the engraved an rolled
copper plates become elecrodes and eecroy,ic &C.
tion gees in the solution of sulphae. deposit o!
copper on the engraved plate then proceeds by the
composition If the sulphets VIII lie the freed acid at
acks the rolled copper plate and supplies sulphate
OF copper to the solution This action is continued,
first in vertical and then in horizontal position of
the plates, until the amour, of copper deposited is su
Gent TO make plate that will bear free handling The
solution in the ho zontal vat is heated constant
heater to from leo deg 10 $50 deg during work. the
original add deposited plates then withdra together
from the solution filed AROUND tho edgs, and separated
along the iodine layer The original thus released and
this deposited plate called alto is in turn u-ed as
matrix which to deposit plate in the same man
ner This plate is perfect copy of original and ia
pas on account of the greater ard pu y
OF the copper This has attained the great
est ce tsnty when in skiul hands 1t been applied
to plates Of the largest with degree of best
appreciated BY inspecting set (amsng those at the
Crystal Palace,) including original, an alto and
bssso duplicate each by SO inches in sire and ex
cept the alto, one eighth of an inch thick
Next and last comes the ming department which
has for its simple function the businefs of
printing, and in which the methods those usually
employed in copper and steel plate printing The ink
hand ink roller plate being warmed TO the purpose
OF sotening the ink by placing it iron box filed
with steamy vapor from distant FIRE and boiler The
mass Of surplus ink is then wiped from the face Of the
plate by rubbing it with rags, and the wipng is thon
By rubbing with tas palms Of the the s ssss
coysred. ~ The Tipns being completed, the plate is
laid the bed Of @ s IT'S pf aes and
re then drawn by q hand crank movement, under
he heavy pressure Of tue press ss, roller. Blankets
Lifting the paper the plate the ink before lodged
the engraved lines appears the impression in ridge
plate quite rapidly SO that ne copper plate usually
Only from 000 to 500 perfect impressions, though
e LARGEST eeetrotype plata yet used notw hstanding
600 uninpared impressions. Steel plates give much
eater number of prints before failing, many
20 COO being sometimes attained; but these not used
the Coast Survey Office because the original cost of
raving them is from third to half greater, and
are from them il also much more difficult.
Considerable attention has been bestowed in the Coast
urvey Office the improvement of the pressing process,
to obvate the distortion of large sheets in printing
substituting iron wood and other aterisls in the
printing employed for the largest maps
Uniformity has been secured and the distortion produced
assrg the paper through the press. press printing
the pressure of plane surface Is still considered very
esraoe ana Mr. saxton has been experimenting for this
purpose paper is also much desired which shall have |
Is hbres composed in telling, and not arranged in
direction, as in ordinary paper
The part borne by the Archives the progress of these
arous opera lions ia sufficiently obvious, being indeed,
1ut the careful administration of the original materials
% which constant recourse is had.
The instrument shop is chiefly occupied in the
ructon and repairs Of instruments for in field and
b. droe rapbic work.
ents i simple and thorough special dsbursing agent
being charged with the entire do tail OF monetary admin
strstiop, under adequate rules and instructions.
comparison of the Coast Survey office as it now ia,
with what was in 1874, would stringIy illustrate the
pros of the survey. Then The superintendent
able daily spect all it, operations and verify in
person the work in hand Nov he scarcely find time
for detailed monthly Lspection much has the
both OF field and Of Office work been increased by the
into sections, and other changes. The
assistant in charge of the Office, down to the
time when Capt A. A. Humphreys, Of the Typographical
Engineers, relieved by Major l. l. Stevens of the
Of engineers at the close of s49 was able to do
the duties devoving the various heads Of Office
however, by ruinous over-applca
ton To Major Gov. Stevens, the present office
ganizaton much of its completeness the supern
tsndent literally seconding his efforts. On his appoint
Governor of Washington Territory, in March last
Capt H. W. Benham, Of the corps of engineers APP
pointed his The experience in administrative
aues acquired by officers Of engineers and phca
engineers has proved ogy opporune for the dis
,haIge of the complicated functions of this position
The superintendent is striking example of the value
If the peculiar species of training observed his education
West Pointer and engineer officer being the best
possible for producing union Of scientific and admins
Iative talent.
We mus, not farther protract remarks Office |
york and organization is needful to do for