The sun. [volume] (New York [N.Y.]) 1833-1916, 1908-03-29

feet we're eli riRht. ARain. The air Wa
let out gradually and, graduated from the
first test, the vialt0fs we're passed on 10
another member Of the medical star. who
stripped them 70 the waist and made q
careful examination with 4 st9thosoope.
On the combined -All right Of the two
phyadAns the party stepped Into the ele-
vator and we're dropped down inside one
Of the big steel eaissons, "a feet long by 70
vide. with two steal skins five feet apart,
the space filed with concrete. Some sixty
feet below the surface they left the elevator
and started Oh on foot toward East avenue,
Long Island City.
The way va through . cast iron tube
2S feet in diameter, the shell made up Of
track laid In the tunnel stood several card
bearing strange soon shaped pieces Of
metal n 10 a car. These odd rocking
things proved 10 he a few segrnente Of a
single ring, each segment Weighing about
a ton. II takes eleven such esgInents and
a smaller key 10 make up one ring.
In this Long Island extension Of the
tunnel there vas a good opportunity to
see the work In various stages Of COM
pletion, In some places workmen we're
filling In the rings with concrete. Q tenn
pOrary mould Of narrow boards being
built inside the tube 10 hold the cement
until Il hardened. Further on the boarding
had been removed and the smooth oyllnder
Of concrete hid the rough shell.
The visitors walked perhaps q thousand
feet toward East avenue and then, retracing
their steps, entered the under river tunnel.
This was Identical with the other In inside
appearance for the hrst 800 feet, Then
the visitors climbed a wooden stairway
nearly 10 the Roof and entered the first afr
chamber.
When the work was begun there was a
chamber near the oaisson. This was
abandoned when the shield had gone out
under the river a way. No attempt IL made
10 move an air chamber 10 keep up with
the shield behind which the men are work
ing; when the chamber 10 left too far In the
the shield.
In this hrst chamber the visitors we're
gradually accustomed 20 a pressure OF
about eighteen pounds 20 the square inch.
For a thousand feet further on this pres-
sure would be suf1olent 10 hold the work
in place, since the rings we're all Get and
holted and for some distance were already
calked with lead. Beyond that, whore
the tube was less nearly completed, more
pressure would be required. In some Of
the more difficult stages OF the work the
groundhogs have worked In an atmosphere
Of thirty-eight pounds pressure.
Again the first few pounds hun unao.
customed ears, hut the feeling soon sub
sided. These air chambers remind one Of
nothing 90 much A a ianciful submarine
passen ger boat, in which one might take
his seat and, when the door had been
changed shut and tightly sealed and the
machinery started In motion with much
russ OF whistling air, be whirled under
water az giddy speed.
From the first air chamber the visitors
walked along a hanging boardwalk just
far enough below the roof Of the tube TO
permit one TO stand upright. The walk,
some two feet and a half wide. swAyed
with the tread Of the ~tenderfeet, for they
did not know how TO use II until, under
repeated cautions from MIR. NOR, SDont
swagger, don't swagger,' they learned
the trick Of keeping their feet nearer to-
gether. With this ~precaution the swinging
walk was as steady as a pavement.
This walk a built for purposes Of
the idea being that should the tun-
mel beCome flooded before the tube was
made tight the workmen could climb lad
ders 10 Il and escape by IL 10 the nearest I
bnlkhead, behind which was air pressure
10 keep the water out. Thanks 10 the eX-
pertness Of Mr.. NOR and his associates, |
foods in the tunnels have been rare &C.
currences.
BY the hanging walk the party came
10 the second air chamber, In which they
and joked while the pressure was
nun up 10 thirty-four pounds. The in
crease seemed 70 make no special diff
and by this time they had learned
10 blow out their eardrums at the proper
li,,o. an noa.ptaraC1 0hA Rpaaatna frOpa
The whole thing Is largely a
OF free air p~assages-a person
troubled with catsrrh has no place in a
From this chamber they descended to
he floor OF the tunnel. The sight oil the
ong iron tube ahead tempted some OF the
party 10 ascertain how whistline would
there. Their attempts at this caused
considerable merriment among the guides
a sound would come. II IL not easy
o whistle against thirty-four pounds pret-
NIre. The voices Of some OF the party
we're high pitched and strained, like that Of
IN overworked tenor.
A long tramp over the cement smeared
'oadbed brought the party 10 the junction
II the Manhattan and Long Island tubes.
The shields had been removed and the edges
" the iron tubes fitted against each other
lightly. Mr.. NOR a~pologized for the slight
Inference in angle Of the temporary floors
the two tubes, pointing out that 4 tube
will twist a little spite Of all you can do.
Branching out Of the tube at this point
4 a pump chamber over a short section
u tube of the same diameter a. the tunnel
md the same construction, but running
right angles to II and below II. This
'ylindrical chamber is known as a stump.
I IL intended to act as a drain for the pair
4 tubes A and B, with both Of which 1t
g connected.
In case OF Unforeseen leakage In the tubes
he water would run into this stump and from
here the pumps would drive il out 70 the
Neither Mr.. Moir nor Ar. Japp
,xpects this stump 10 be needed. 1T Ia
My an additional pr~ecaution,7 they eI-
Using the stump for a cross road, the