The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1876-06-19

every nvc to ten minutes TO ascertain the steamers
exact POSITION such continual observation being neces
sAry. owing 20 the ever varying currents
OBSTACLES TO NIX OVERCOME.
over that portion OF the Channel sounded last year
gradually toward md channel where there is zone
whence there gradual ascent 10 the English shore
the greatest depth Is IN a few hollows on line Tom
Blanc Neg to Folkestone. On days when rough
weather would not allow OF accurate soundngs. or
thick weather hid the coast, Messrx Potter and dc
Lapparent used examine the cliffs During the six
weeks operations $50 soundings and 1853 specimens
OF the bottom obtained; 335 Of them have been
classified with certainty Tho average daily castings
OF the lead were seventy The boundary line Of chaky
stratum has been asccrtancd by the lead bringing up
either sandstone clay, which form the strata on
the Frencn coast which point English waters begin
and the consent OF the English government In tins
care mere ormality was necessary previous TO max
ing surveys, which permission has been lately aned
u sETTLEn
Last summers observations and soundings have set
tied two points-First, that break exists in that
which comes 10 The surlac- the bottom OF the Cham
mel IN tho parts where soundin.s were taken and.
second, that tho dip observed in some OF the strata
nowhere exceeds ten per This years soundings
VIII probably be undertaken from Dover, rs beng
closer TO the OF operation The belt OF souudings
which is from 10 i've miles broad, mas been made
from two to Jour miles west OF the line where the tun
mel Is intended 10 be made. For the Information OF
non gcologies may be explained that the soundines
have been made that part Of the Channel where
the chalk crops up and the distance OF two TO four
miles further east is allow the stratum to dip suE
lciently 10 allow Of their being a good thickness be.
tween the crown Of the tunnel and the bottom OF the
Channel The programme Tor
rus YEARS CAMPAIGN
is:-Frst series OF soundnss very close together In
English waters TO sotte doubt as 10 whether d.
vcrgence OF the chalk toward the north Is due to
break or is only dip; second, Of soundings
over the projected line of tunnel to ascertain whether
tho stratum called ny the geologst Phillips, chalk
with numerous nints' ana which overlays the stratum
through which the tunnel Is 10 DO cut, to the
surface. third "a series of soundngs the space
between those made over the bed OF chalk last year
aud those taken the line of tunnel. fourth.
sounding over any spaces not already examined; nth,
boring on shore IN the immediate neighborhood OF
Sangatte, which shall be sunk al least ten metres be
meath the gaut
When tesc works have been accomplished well
Will be sunk and heading driven under the Channel
THE BORING or THE sANGArTE.
In February last, shed containing u powerful der
rick, winch and all the appliances which have been
Tor years used by the arm OF Mu0t Perc ct Fills ct l..
Dru, OF Paris who the for this work.
their shaft sinking operations, was erected spot
few yards distant from The beacon marking the
end OF the submarine telegraph cable Day aud night
shifts each Of six wOrkmen and foreman. have been
al work ever since the 18th Of February when ground
was broken and on Saturday afternoon, Juno q they
bad reached depth of oil metres GOO English fee
CRAZE de souc teray chalk which entered at tho
depth Of 3d. 95 metres ais lcet As of the objects
of these borngs is to gauge the of that
Is likely 10 DO met with In tho fEal operations, tho
shan has boon lined to certain depth with iron
tubing, let in telcscope-wisc, OF different dametcrs
The annuar space between the tubes has been filed up
with cement sroune to mako II watertght and to
sodate the whole.
GETTING OFT THE EARTH
The operations are twoiod--hrst breaking, turning,
twisting and crushing tho ground the bottom OF the
shalt by means Of an instrument called trepan, acted
upon by powerful lever; when this has been effected
an iron scoop ity feet long Is let down by rods aud
turned round till the foreman considers FULL when 1t
Is Withdrawn. This operation occupies forty minutes
On reaching the surface the scoop emptied It's
tents carefully examined and specimens collected The
SCOOP after being well washed, down again, the
return operation occupying ten minutes. Two rods
only have been broken during tho whole operation and
these withdrawn without much difficulty. Two
tubular pumps the works the larger having
been discarded. The pump with smaller borc oc-
casionay sent down the shaft TO pump dry and
certain the amount OF nhllraton which hitherto has
boon small and VI spring water only, notwithstanding
the proximity Of the Now that a softer stratum
has been reached progress will DO rapid, and next
week iastcr though powerful machinery, viii be
substituted for that used