New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1858-05-03
',.I !, simple way the dynamic action Of the

r. tn s,stions in and GEAR Sandy Hook bay.
The comparison Of the times ana velocitles oil ths
o,r..,s IN the main ship channel into the time atd
S.S fsu az tbe tide, develop Interesting laws IN
.; 10 the normal state OF the currents OF ebb ADD
49, - the entrance OF the bay. These currents pay
sa,tant mart both directly and indirectly. Their
eS,t .ri;oa nyoduces the secondary or draugbt
s;nh move the material of the hook toward its
~,be,. extremity and cause its increase. The rea-
tos n thess normal currents to the tide was exhibited
-; Az tsbes and diagrams. The earliest change Of
lent takes place neither at the entrance Of the bay
nor & The west end Of the main ship chsnnel. The
ssesre of one form OF current into the 0ther
nsiscsesry shown in the diagram.
Tatse a. well rs other results, are generally from
simpi.aDcc observation made by Assistant Henry
Mitchell OF the Coast Survey.
TIE diagram for the False Hook channel show the
results from Long Branch in the south 70 the northern
point OF the hook in the channel ON the shores and
On the shesls. Their comparison with the normal cur
rents shows now far they partake OF their Character
s1d bow far they are secondary or draught currents
PRODUCED by the lateral communication OF motion from
the main streams. The flood exceeds the ebo in dura
ton by eevon minutes whereas in the main ship chan
oel the cob exceeds the food in duration by nineteen
minutes. The average maximum velocity Of both ebb
and focd Al miles per hour while 10 the main ship
chaassi il ia LII miles The ebb makes out but slow
ly tkresgh the False Hook channel. The action Of
the dooc in transporting materials is nearly six times
that OF tbs ebb and hence the growth Of the hook.
Whenever it becomes important TO limit this growth it
can BE done by series OF eties which will arrest the
shore curreft and cause 1t TO deposit the material
which 1t u transporting The action Of the waves in
strebdipg this material is not TO be lost sigh OF.
To 0o.an q clear idea of the currents Of Sandy
Hook Bay, il lie necessary to divide it into three
tioas. toe eastern near the Hook, middle section,
and western section near Raritan Bay. Inc group
Of stations IN each section gives the direction and
locty OF the tidal current for that part Of the bay. At
fret siget the phenomena appear confused but q
careful study readily connects them Special diagrams
were prepared for this part OF the pay showing tne
low water Specimens of these, giving the currents at
the remarkable epochs were shown TO the Soc
TIE lio0d current commences in Sandy Hook Bay
and in the main ship channel about the same time,
namely. nearly two hours after the moons transit.
The wster in the main ship channel runs west ward,
that Of tho eastern part Of Sandy Hook Bay TO the
southwark that Of the middle TO the southwest, and
that of tns western section to the west. This con-
ii,iou lasts about two and a half hours. whirl ex-
lists OF the end Of the Hook which Increases gradually
ia cine, AID its axis moves southwark.
-Four hours from the slack the direction OF the cur
rents IL the currents in the eastern aud middle
parts of the bay running north the current OF the west
era part running west. Toe rate ip the middle and
parts Of the bsy is SMALL while the water OF
she main ship channel is running westward at a rate
of L. miles that in t1e middle and western psrts of
the bay has & velocity Of less than half a mile the
hour. Five hours from the slack the whirl occupies
the mdoe Of TIE bsy, or is nearly circular, reversing
the foer direction Of Il currents then. At fix hours
The cayeats ia the main ship channel are rapidly dl
rnins Bg in rate and al seven hours the ebb current
prevail The directions of the ebb 10 Sandy Hook
Bay may at first be nearly represented by ,tIaight
lipes ccnye giDg to point north OF the Hook In the
main ship chanrel but they careen to the south
ward The portion of greatest curvature passes to
the wei .wsSd gradually as shown by the diagrams Tor
y and fer IL hours
THIS general movement finally creates counter
drift ne AZ the point of the hook which 'sunes the form
of w.iir as the current in the main ship channel
slactefs Tho ebb current near the shore OF San1y
Hook has velocity of one mile per hour, and the
food of but fcurtenths OF mile. The duration OF the
ebb s teo hours and of the flood buttwo The lateral
Of motion causing these secondary our
rents az the ase of the False Hook but with greater
efficiency. Tie transporting power of this ebb is to
thst Of the food fortyvc TO one; but the nature
of the material on the interior of the hook the rapid
decline q toe force Of the currents in recedng from tho
point and other causes preveLt this current from be-
g a. elective in building up the hook as that which
sets on tie outside. 1t is not, tten to this SIDE OF
tie ho tsst the remedy for its increase should be
NJ piled.
Beside she value Of these results directly, in refer
epc 10 tss question OF the increase OF Sandy
HI ok taty of Interest," to navigaors, as correcting
in form not difficult to remember, directions dura-
ons and velocites Of the currents at the main en-
trance Of New-York Bay and HarbOr.
The form e the bottom of Sandy Hook Bay IL
mainly determined by the current action which ha'
been traced.
The spread ng of the currents from the wave OF
food tide ard the concentrating OF those OF the ebb
a. eue oil facts, de0ucble from the rate of III otion IN
W. TER Of fftrent depths. High water and low water
stream.
Professor Bache acknowledged the obligations of
the Coast Survey to Assistant Henry Mitchell OF Nan
tucket for the ekllul manner IN which the 0oserv8'
tions directed have been made and his personal oDI
CATION 70 Nr. Mitchell for the unweared assiduity
which he had shown in the discussions now brought
before the Association.
DR.. Wo'cott Gibbs followed with paper upon
Polyacid Bases, which appeared to be continuation
Of his learned aud ingenious paper read at Albanyin
oh ha fed all nv
their aoidsenlarging and, in one or two points cor
fecng the views of that essay, and giving handsome
ackuov Judgments to 7. 5. Hunt of Canada for pr-
Gritty in several modern views upon this subject.
Mr.. j ID. Runkle of Cambridge, Mass, gave his
views OF the necessity for establishing mathematical
carrying il out in an educational point OF
view. The journal should contain clear, concise
notes from wit rs, ofsbihtyupon all points OF theory
queries Isolated problems which are too good TO be
lost; also carefully elaborated essays treatises,
which may afterward be reprinted in book form. He
asked for frank and full expression OF 9piaic from
/ he members IN regard 70 the literary ana hnanciai
disability OF his plans.
P1oFs Cssweil, Coakley, Woodman, Lieut. r. Is.
Hunt. Prof A. ID. Bache, Prof. Il. PIERCE, ana the
Chsirrasn Prof. Bledsoe spoke very earnes,y anu
,,nrdaIy in support of Mr.. RuDies plan, as Deihg
smpest,y practical likely to enlist the support OF all
casses OF athematcians, even TO the undergraduates
of our Colleges, to advance the growth OF inatue-
MATES in our country and to be OF genera use IN %
Advancement of science. On motion OF Prot. Css~oH'
the subject was referred by the Chairman 10 meSsrs
Csswe,l. PIERCE ard Coakley. II
Prof. !. H. Coffin read paper upon the currents OF
the stmo over the North American continent
particular. and the northern hemisphere IN general
yety interesting discussion followed, 10 when IroIs
Lecoate Of South Carolina PIERCE, Caswen anu hony
took psi, Prof Peirce suggested the importance oi
sendipx UP small balloons sDd watching them oy Two
or tbres teescopes. Prof Henry remarked that Mr..
Wise tae celebrated aeronaut had already engaged ~
w nm Limsef This Summer and carry with him nstru-
rsnts furnished by the Smiths onian Institution and
no''' - cbseTvston on the currents dew point,