The times., 1898-08-19
AIR BAGS TO FLOAT THEM
How Cervera Sunken Fleet Will
Re Raised by HOhson.
HE DETAILS HIS PLANS
The Lieutenant in Conference with
Navy Department Chiefs Over HIS
undertaising-speaiS of His Pro-
motzon-fie Mny Soon BE Made "a
FuII Naval Constructor.

Lieut.. Richmond p. Hobson spent yes
terday in conference with Secretary Long
and other chief officers of the Navy De-
partment, having come here from New
York to have a last consultation with his
superiors relative to the work of reclaim
ing a part of Cervera's fleet from Santiago
beach.
After a busy day at the department the
lieutenant returned to the Army and Navy
Club and ate supper. He then engaged
himself with a voluminous correspond
ence, and worked until quite late with
the executive end of an undertaking. the
accomplishment of which other engineer
ing experts have declared impossible.
When pressed for an interview. Lieut.
Hobson, in his customary modest manner
spoke of the work with which the Navy
Department has seen tit to honor him
that of saving several magnificent
though badly damaged battieships for the
new American navy.
THE work of wrecking the ships shows
no new features just at present. he said.
Some little time will elapse before the
real work of lifting the vessels begins.
expect to be at Santiago within a week
or ten days. and then the raising of the
warships by means of air-bangs will be
begun.
The delay at present is caused by
our experiments with the large canvas
and rubber air-bags, which / intend 20
use. These experiments have been going
on n Staten Island and as soon as the
right kind Of bag has been found an order
will be given for their immediate manu-
facture. About two hundred of them
will be needed. and when the order is
once given they can be manufactured al
the rate Of twelve a day.
They must be exceedingly strong for
the reason that when they are placed in
the interior compartments of the sunken
vessels. which they are intended to raise.
they are inflated by means of tubes and
air pumps. and are then placed under
very great interior pressure. As long as
the bags are under water the specific
gravity and pressure of the water is such
that they will work all right and stand
the strain. but when they float the vessel
and reach the surface the air pressure
within will be much stronger than the
resistance OF the air pressure without and
there IS great danger of their exploding.
We are endeavoring TO secure bags that
are strong enough 10 resist this pressure"
Lieut. Hobsen explained that in expert
mentinE at Staten Island the air bags
were taken out TO the deeper channels of
the bay and sunk TO the bottom on heavi-
| ly-weighted anchore. They were then in
fated and the anchors fioated TO the
top. In this manner each make cf bag
was given thorough test of strength and
tension.
Lieut.. Hobson will leave for New York
at midnight tonight, and viii make final
arrangements there for the manufacture
| of The a5roags before going to Santiago.
| His present trip here is in all probability
the asst one that he will make here he.
| tween now and the time of his sailing
| for Santiago. ,
When asked about his prosp 7ctve pro-
motion he replied that he was too bust Y
| engaged with present dut es TO give the
matter much thouGht. He did not expect
| to he promoted before the next session
| pf Congress.
The lieutenant will be a full naval con-
| str-c:or in few days. notwit standing
| fle delay in honOring him for his brave
act at Santiago, by reason of the retire
| ment Of Naval Constructor ]. 3. Hoover.
He was retired on June % last. at watch
| tine Lieut.. Hobson. the nior assistant
/ naval constructor, was imprisoned at
| Santiago and could not be exlmiled for
promotion.
The board of examination which will
/ decide upon his fitness for the new posi-
| ton met at Portsmouth yesterday. The
| press of the young Heutenant's duties are
| such now that ne cannot appear in person
/ before the board, and a number of docu-
] ments have been submitted for the con-
/ sideration of the examiners in lieu of the
presence of the candidate Among these
| documents are the lectures which were
| delivered by him, to the. students of the
| post graduate class at Annapolis last year
on the subjects of shipbuilding ana naval
| cons. .ruction.
| As soon as the board has passed upon
| him Hodson will be full lieutenant of
| the Construction Corps of the navy, and
| when Congress convenes there is a possi-
| bility that ne may be advanced several
numbers ahead of some of the eleven full
naval constructors which at present con-
| stitute the corps.