New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1898-01-02
TESTING FOR THE TUNNEL.
CONDITIONS OF MANHATTAN ISLANDa
SUBSOIL.
WHAT MR. PARsoNs's behring's HAVE SHOWN
THE COURSE THE TUNNEL
WILL TAKE.

soil 10 be encountered BY thorough system Oh
borngs at points all along the proposed route
Of the tunnel William Barclay Parsons. tho
chief Ell ,ineer. has ascertained to his own sats-
faction just what the substructure OF the city IL
in those neighborhoods. Some Of the borings
made to depth Of considerably over one
hundred feet. far lower tnan the requirements
of the tunnel demand. Mr.. Parsons has IN MS
office several cases divided off into compart-
ments, which are filled with the material aug
up at the various points. Before mentioning the
character OF the soil in the several districts IL
will be more convenient to recall the exact loca-
ton and of the tunnel 1t may De saio
to begin with the loop around the Postoillce' lor
the construction of a subway below that poin'
Is not contemplated for the present. After max
ing the loop around the Postoiiice. IN oroe' !"
turn the cars. the tunnel continues UP Centre
St to WORTH where it enters Elm-st, which mas
recently been widened Thence it proceeds under
what is now solid block, but whlch VIII NC
cut through. from Elm-st. to Lafayette Place.
and I'D Lafayette Place to AstCr Pace anu
Eighth-st There it turns into Fourth-ave.' UP
which it runs to Forty -second-st turning "eS'
at that point it runs to seventh-ave and broao-
way From there 1t crosses in d diagonal line
the blocks from Forty second-st at that point
TO Fifty-nInth-st and Eghth-ave Continuing
the diagonal line northwest it reaches the Bouie
ward a little below One-hundred-a feminist
Thence one branch runs straight out TO peyoho
One hundred and -ninetieth-st.. in the neshoor
hood of Bronx Park. The other branch' lea'i''e
the main line at One-hundred- and-iour'h-s''
runs east to Eishth-ave.. under coihef "a
Central Park, up Lenox ave, TO niue Oe'o"
Oue-hundred- and 70 -ty ffth-st, where IL tufhs
cast 70 cross under the Harlem River. then east
on One-hundred- and forty -ninth-st. 10 Ihiru'
ave. its terminus. From the Postofhce TO '$
boulevard and Observation-Disclosures
where the line divides. there are 10 De lour
tracks. and two tracks thereafter On each
branch.
u,e q weyl-known fact regarding the geology
NJ Manhattan Island that much OF the lower
mart OF the city rests upon great pea oi peao"
Sand This sand substructure was iouhu ny
the RAPID Transit engineers to continue a" the
way from the Postofiice to Twelfth-st Inc
sand was OF varying degrees or hneness' any
extended or an average to the depth OF went
feet Below that the boring struck peuroSh
Uror, Twe,ftb-st the gneiss which is the char
acteristic rock Of the island begins TO crop
on, At the surface This lasts up to Twenty
th,rdst Then the rock disappears for a few
blocks comes up again at Thirteth-st ana
l las
Fortv-second-s there is bed of clay when
Zoos down 10 depth Of fifteen feet resting
then on rock In Broadway. from Forty-secohd
| n Sixfieth St the clay goes down t"ei'e
foot where the rock appears. The soil under the
| boulevard varies rock ard clay alternating up
| ,o the end of that western branch. Where the
! eastern branch turns. under the corner OF zen
trail Park the gneiss rock crops out but az
eoon as Lenox-ave. is reached the soil is almost
nure sand all the way up to One-huhureu a"u
| fortv-Gfth-st In tunnelling under the har'eii'
| River both rock and clay are fouha anu oe' inv
! that point to Third-aye.. rock.
| The funnel is to be fifty feet wide where there
are four tracks and twenty five feet WIDE whera
/ tiare are two. and the minimum heisht every
| where is TO be thirteen feet The minimum"
thickness Of the roof partition. separating inc
tunnel from the street IS thirty Hlc"eo' ~
will vary. OF course. according to ioca' co"u
lions. as will the general depth OF the 'u."e
but il is the aim to keep as near inc s'ree' ''''
as possible The stations for boarding anu 'e"'
In. ,ba cars will be about fourteen feet oeio"
| the street III.
| vivian asked whether the same trouble Win
ro.roct IN dampness would be encountered aS
,hot which had been alleged against the h's'on
subway. MI Parsons said
1--WE should guard against II as H'u G" fO'
| ~, no having the stations brilt OF WOOD anu
,Ao roof and walls Immediately around them
lined with wood The dampness comes from INC
sudden condensation Of the moisture IN 'he ou'-
eide air upon the cold walls of the tunnel anu
II the surfaces near the stations were u "0oo
no trouble would be greatly lessened
Mr. Parsons inclined to thlhh tna' 'No
amount OF dampness in the boston suo"a'
had been exaggerated and ne saiu '"a' o"'
on a few days IN the year wouIo lneis w '