New-York tribune., 1871-12-01

~ he directed by means OF telescope 90 o. throw tho
reys OF light toward the theodOe used by the observer
With this instrument tho rays have been reflected
from mountains miles from tho Observer series
OF secondary tertiary tangles all along the coast 10
then formed this primary triangle determining the
distances Of prominent points from two to five miles
apart The base which served as commencement VI
the primary trianguation for the Eastern and Middle
States lies within the State OF Massachuses little to
the north Of Rhode Island. 1t is ten miles long
and Ne direction nearly northeast and south west 1t
was measured In 1s46.
NECESSARY MEASUREMENTS.
After triangles formed and distances measured 1t
is important determine the exact direction Of side
OF the triangle with reference to the pCnt OF the com
pass Astronomical observations are accordingly made
from the base line, and its direction determined with
reference to the meridian Accommodations Of error in
the trlangulaton are prevented by measurement u!
base of verifcaton connected with the main ridngn-
ticn and the longitude may be determined not only by
astronomical observations but also ly the electro tco.
graph 1t our coast survey that first made practical
Of the telegraph for measuring Intervals OF time nd
recording astronomical observations The method mas
The labor Of calculation and observation in fixing the
primary angles is very great An element which add-to
stations Of the primary trlansniaton are different
nights. II Is ncccssar, to measure vertical IA well -.
figure OF the rarii to reduce tie plane triangle. vncn
are the direc! ,uit. Of me measurements to 'ph''oa
After the series OF secondary tertiary Triangle ore
conrlcte 50 as to tax N the outline OF tn tIaT m ne
further details supplied BY the tirgi'pal, w."
represents on mperall te natural fc.ti So me me @ KIN
htNt!tu' me II! 'PHt an y, 4 nth ,,f wIirr lhc
his nlulsltNe cau' u't'i hl"' "e Y innc,tr,t,s L,
~ :. y. l,hr ,i,n r ,, 81 me- ~ the shore, a, pc-
vously surveyed guide. hnl Every t'h" i' az; ~.
lead he can e,,ine the exact Icsii' oI,. e" % nm sn i,
shore sGna The nature Of the iGl,"m M ~1h rf' r,,
rents. !cs. 9nd prevalent wni', ~" d dl'r ~, t,,on
il nnd d t,ilcd silryc, are carried up tlr
rItI, wherever tlCy are dccInod hc'tN'ai!'
TIE '"fs'
| ~ - ,, ,it.. rh, r.s,l, =, t,,,. direction
ri,, ,t,c, h,,cc, Of IN, work, In ,r,.rln
;, ND ,cr.,ry the oscrya il,s ol the Coast suiycy
on tie tides are far ahead of any Other, The genera
theory of tidal r.'ycmn has been wen d.' .rnnrd
C" inc co;, and Tie d,lh oi hc ocean. receive rrtial
% ,is o,s j,yr been rr"r,rrI for ire I of irr-
n.l. There , "o.r so ti,l ,t;,r,on, on DE A.no
'naH' ana r'i" iril corps 81 NE Coz ,' M
rs I''?S 1Sacsi rs ns@,4rs i"avc% rccoia Of
M n, li arooi Tc'' , ~ . S' az n,.
Commonly used by ine survey COZ. ol iidt "ors t
rrpresrnis S the cS varying @ The water
y Gi'ok h M M.fs & a, @ , c c G mr om ' r"rr %r " r S,
every day an aut:l"rh journal of IFS utS ana 10y Us
with more franknts. ana tXari,s", ana !tSs esotism
| The noabox becoming cior,,d with ace stream "f
water made 10 pass ihrougo con round lrE" sl'Vo
n h ani nov r. m. W n,crmrnt has rr,ynd y'ry ,,cr.
NC 1nc>T scIiT kl>tt1lnS HtN'
lM thcr rrCHrd for ttN'iai icIi. 1ta,ihS wiln mh
Iv rom ihr Grd,r, lnunr nid ,,.r ucrsasls ID
| y iuc Violent tl"qucncc of an earthquake.
ACCURACY or TUE TIDAL RECORD
a r'''a' "'''', Instant u ''o 'I."' V.
tHries OF the deep Wis sec'i III l''i ON ' ga oi '''
cc,D of hat year. an carihau1ke occurred ~ ;pan
by which the town oi Simodt was d'S'r'!cd severe
shock was fit IN the morning AZ 9"c'cH' ana soon aT
an ilnnc wave 80 feet In hight. overwhelmed t'Io un
sispcctlnS city. Ii rccdtd. gathered itself again, ana
az
pened hye times Tie day the tIdc-gargr at san
only be accounted for when the wso the oarthquah"
s1 T from % ,S ss iGr s 1. p Of hours &
and ss mn1ies it NUT ther9iors & haYs rye'd , at an
loe!y with the theory Of wavo moio;'. NE av"Ias"
acRth OF tho racine ocean was calculated 10 DO i'o
the c?ranc OF % ha,s and Rarors has rscycd from
the Coust Survey the attention which It's great import
aIc AMY ,hn chancs are rssnnneH a. Ditch a.
Thus, though complete chart Of NewiOrk Harbor
hadc very early Dl thc 'yist yc. ihJ la o' . "
IN. W and s",,,e'i ont and cI.nncled Ly Inc ei
M shnniI creaic new d,i innd sanJ,ars : ~
prof j. r. uirard Assistant on the Coas, Survey has
pad partc nlar attention to the subject OF tides and has
iat"w pmlscd a valuable paper on tides and tidal
aca.an. in which the phcnonrna peculiar to New-York
turned is attention to the subject the Of
Hrnr"srpns l hss conirued an important ruier On
this sujcct-ihe result Of much study and observation
| g., w, o,,, aan,,n =, ,,a o,,.. r,,,,
er cnrrfu survey OF ANY ss''on ol ''e 0'a'. w,'n
'h ,'i. =. ;. ., ..,
amount ol aoor niSt DC spent III preparing 'ho maps
and charts publication. The cGof value OF these
hr,. o,ns,s. in their thorouphness and accuracy OF
.'' " ~ " .-. - -.
deaii 10 secure lhls INC u,hiosl caIo NUS pc roh'
stalily lainh,neo 10 S'itrd afahS error III h ON
puia oli wcarranH"u system o cili Ms Is rip'Hcu'
50 that IN error Ill caicuidtipl can scaco1 cScaPo
toi ING h.1 pa .cs, III tc ~ ~ u' e. oinp' ~" ~
oll ~ w H. N, " a " ~" "nuo, tin with m. II 10 vnrt ph,
Two computations then submitted To the assistant
charge Of the Once VINO compares thein ana reports
Any ,iS T " exncuedd hx the tej no ~.
copied revised and reduced the scale OF publication
b! INC oriuthtshah OF lhe onie hioh'r assi'C,h mas
Ch"i So Wv - ..