The southern press. [volume] (Washington [D.C.]) 1850-1852, 1851-03-04

Chesapeake, or Of North or South Carolina, in
our nautical surveys. Topography s, as geodesy,
profession. Our work would be inferior to that
of enlightened nations generally if executed by
nautical men, instead OF landsmen, by tyros in
stead Of trained topographers. The whole system
of the scales of shade. introduced by the German
topographers and perfected in our own coast sur
vey, deineating accurately the slope and features
OF ground, Is unknown TO nautical men, and I'M
practlsed on any nautical chart made by them in
any part OF the world.
Geodesy is an application ofmathematical prn-
ciples which Is out of the range of the usual stud
les in mathematics and natural philosophy. 1t
a special branch. The elementary books contain
only lately some exposition oft, and that in this
country, from the impulse given to the science
and the practice by our coast survey. 1t is no ex-
aggeraiion to say that no mere nautical man can
even read understandingly The formula upon
which the computation Of difference of longitude
difference of latitude, and difference Of azmuth
are based; and If il were required that exami-
nation should be held for aspirants to this branch
of the coast survey, it is certain that the number
would be very limited who would present them
selves to this ordeal merely to explain, much less
to deduce the formule upon which the computa-
tons are based. Nor would it be dscredit to
the naval man that he was not versed in these
things more than to the philosopher that he could
not direct the sailing Of ship.
A coast survey without these requisites would
bring discredit upon our country. Better to at
tempt none than one which would, in reproducing
the methods and practices Of a century ago, make
us the laughing-stock Of the civilized world.
There is no single operation in the Office of the
coast survey which is not beyond the sphere of
the nautical man professionally, EXCEPT merely
the reduction of the nautical chart. The reduc-
ton Of all the land work is made by methods with
which he is entirely unfamiliar, and which are
Ah fpl al <lolt> tI,at Il
the degree of minuteness corresponding its exc
cution. The very preparation Of the drawing
board and of the paper on which the deneation
is to be made, involves physical principles which
in the course OF his profession he has not exam
med, and yet which are essential to its success.
10 ascertain that the importance Of these details
is not overrated, let any one VISIT as have done
the Coast Survey Office, and the time, alien
ton, and investigation which have been bestowed
upon them, and the results which have been OBJ
tanned. II the land-work were not executed and
reduced by such methods, the accuracy attainabe
on the water in execution and reduction, would be
far from being reached
Drawing is an art requiring special devotion.
Few officers OF the navy pursue this. On our own
survey even, the nautical charts are chiefly drawn
by civilians, who are now for the most part actu-
ally paid from the funds Of the coast surrey. Many
naval officers who are considered accomplished
photographers, do not even attempt to execute
these reductions, The chiefs Of parties themselves
consider i. no disparagements that they cannot do
the work of trained draughtsmen. tits neverthe-
less true, that unless the person who directs these
reductions is specially trained to 1t, and has the
taste of an artist the work is inferior in its style
and execution. Practice has shown that to make
credltable reductions for publication, the direction
must be placed with person specially educated
to it. II is a profession apart from that Of the
nautical man. The course of drawing at West
Point forms some men adapted to such position,
but those who have ranked high in The course OF
drawing desire time and study, and close exam
ination of the work as executed, before being
willing to enter upon its direction. To underrate
the difficulties of q practical branch is common
with those who, knowing nothing Of it, would
neyerless undertake its direction.
The whole business Of engraving is beyond
the profession of the navy officer and yet he who
directs should know at least the general principles
of this art. The whole of the processes have been
matured at the coast survey Office by the expe-
rience of the engraver themselves, and the intei-
gent observation of the assistants in charge of this
special part Of the york. The result is that the
engraving department will bear comparison with
the best Of Europe, with the French, and with the
Prussian. The style of our maps has been praised
at home and abroad.
The whole business of printing is beyond the
profession Of either the army or navy officer
Important improvements have been made in it by
the experiments In our coast survey Office, and
experimental inquiries have prepared the way for
further ones still. As an art, this is Of course
committed to persons regularly brought to IT, but
routine will not answer in work like this Un-
less the methods of printing are better than those
adopted in foreign charts, the measurements made
on different parts of the same sheet of chart, and
in different directions in regard TO the edgea of the
paper, will not be exact.
The entire business of electrotyping belongs to
experimental philosophy, and is entirely beyond
the profession of either the army or navy officer.
1t has been perfected in the coast survey office by
the labors of philosophers, both workInen and di-
rectors. The arrangement and management of
the gavnnc batteries, Of the decomposing troughs,
Of the plates on which the deposite is made, and
Of those which are consumed in the process, all
require knowledge of physical principles and
practice in experiment far Beyond the usual range
of reading and experimenting in natural philoso-
ply. A process has been obtained which secures
the plates from adhesion. 1t may be said that this
could be contrved by others. True, as long as
the services of the present able electotypis could
be secured; but without them not. 1t would,
however, be a bad argument for the transfer Of a
work, which had attained great excellence, that 1t
could be continued mechanically by others. The
argument too would be fallacous, because,
however excellent, there is always room for pro-
gress and greater excellence, and to stereotype a
WOfh Ut any pplHt Oh ptOHTesS ls W Hlsuie tHab
ten years it will be behind the SCIENCE of the day.
Now, then, electrotypng ia essential to the null
tpcation Of copies Of maps and charts from cop
per plates, saving the enormous expense of en-
craving over and over again the same plates En-
craving on steel has hitherto been only applied TO
small objects, and if large steel plates could be
made, such are required for the coast survey
maps, the great time required to engrave upon It,
and other expensive incidents Of the art, would in
duce preference ofengraving on soft metal like
copper, and copying by the eectrotype process.
1t has been proved that by this process the time
required for the engraving of a map may be re-
duced in any desired proportion, since a copper
plate may be divided into parts, each part be en-
graved separately, and the whole may be united,
and plate be derived from them BY the electro
type process, in which the greatest accuracy and
minuteness can detect no
Even in the practice of hydrorpphy there ore
calls for scientific and experimental knowledge
beyond and without the attainments Of the naval
profession. The method Of observing, plotting,
and reducing current observations; the represen-
tation Of currents in charts; the reduction and
computation Of the tidal data Of the ordinary kind
and OF unusual cases, such single day tides
the investigation Of the character of The bottom
and especially Of the minute shells found IN the
To- IL. -.