The Washington herald., 1913-08-03
WITH WHICH SCIENTIFIC MAPS ARE REPI


| tries, States, cities. and townships should
be.
II should not seem strange that the
lAyman should not know how and by
what means the maps Of their country
are Reproduced. but upon investigation
the remarkable fact develops that only
about per cent Of the very engineers
that survey and make the plane tabis
sheets. are familiar with even the prin-
ctples OF scientinc map reproduction.
J When an army is about to move upon
the enemy. when some great engineering
feat 10 10 be undertaken. when for hun
dreds Of other purposes II Is necessary Ia
know the exact distance between two
points. whether one thousand feet OF one
thousand miles. what an advantage II ID
to Vt In your once and have at your dis
posai maps tnaa are 20 accurate that you
can oy very haie measuring hnd the ex--
act distance ana AZ tne same time see
tpe feisuse posit'on 70 any other fea-
tures tnat may occut IN tne area Ant
.nns eooue All tnis
ooy . map ano enart nias.
~ .ns go loie thdn
=. s,a,. -, a,,,... sou u
.ss,, ~ .nn.c,s,s ~ .h.e nu ,,,n one
- .ha,,.., ,d,t =. :. =, az ~ nee o'
.mr,h.r ~ rest IN The grn,,nS .Ass-
- .t~ .ca,a ~ ,ha nan snd aruins ~
s1,.h. =. ,h,s wonId 1re.tIw aa,..a. 90 q.
the accurscv Of the man. as on ,hs ..eis
~ ons ,,,,s 20 the ,nrh-.n .ran, =, 80
fbousandtb OF an inch would mean . d;.-
crepancy Of Ss.3s feet. The need for .uch
accurate maps. II mat be true. is Iir,it,d
as they are used principally where inter-
national and legal questions arise and for
various scientific investigations and re.
searches; but one ia reminded of the elI.
half-forgotten tales of the artists OF
ages gone. who worked ten years on one
canvas. AZ you look at the exquisite art
with which each line In drawn, here a
broad. bold boundary. there the delicate
tracery Of the contour. you think. Thai
must cost million dollars an inch"
AS q comparison with some Of the
other processes employed In the re-
production OF map work. there is abb
solutely no process by which the de-
tail and character Of the maps car
De 50 dehcateiy and clearly illustrated
as by the one above referred to. Our
national currency Is produced in the
Identical manner as Is the products of
the topographic Engraving Company.
ana the same amount Of skill and nat
urai ability IN required in the men
who have devoted their lives to a pro-
fessfon. the products of which are
used and handled every day. notwith-
standing the fact that so few of the
useres are familiar with the means
OF their production.
For less expensive method of mar
making. and one by which the ac-
curacy Is unquestionable. the COM
pany Is equipped to publish all kinds
Of graphic. as well as geological
typographical and hydrograpbicaI
maps and charts by photo phy.
The layman is more familiar with this
process than he is with the former
because of its constant use for a num-
ber of years. The engineering o,
field work Is executed in exactly III.
same manner as any other man work
but the method of reproduction Ia en-
tirely different. The original drawing
or plane table sheet is photographed
to the scale of publication. From tbs
PHOTOGRAPHIC negative a nrint is mads
on a pelatjne-coated n,nsr - -
been sens;ti,ed Ter o,,,..-
cior,.,. - Sou.on OF pi-
~ VI anmonid. "here the light
passes through the transparent parts
OF the negative 1t oxidizes the BIZ
cromate and renders IL insoIuabIe in