The Atlanta constitution. [volume] (Atlanta, Ga.) 1885-19??, 1888-05-29

Something About the Invention Which Con-
gress is Considering.
shington CIR. Now YORK Herald.

something About the Invention " men con-
gress is Considering.
Washington Orr. New York Herald
In an interview today, Mr.. r. G. Dyrenforth,
formerly commissioner Of patents and the attorney
for Mr. De Bausset. replied, in response to the ques
ton, Upon what theory Is the proposed experiment
based"
Upon the well known law OF physics, that if you
exhaust an air tight compartment, the weight of
which shall be less than tie weight of afrit con-
tans. it viii seek higher altitude. If throw six
pound shell into water it will sink. If the sfme
amount of metal is expanded on 20 vessel displac
ing volume of water greater i'll weight than the
metal, then it will float. That is the theory on
which naval architac.s build ships and in my argu-
ment before congress / referred to a statement
made in the Herald short time since, which served
to give congressman who saw the launch OF the
Yorktown definite, practical idea ocjust what dis
placement of water meant in the calculations OF
naval constructors. Here is the paragraph:
at is now known that when the gun-boat York
town is completed i'll every detail as contracted 10
by the Messrs. Cramp, the weight OF the material
viii not be one per cent in excess Of the construct
ors calculations and this in q vessel Of LOO tons
displacement. 1t is said among naval officers that
this close adherence to plans and precision in CON
structon is very seldom ever attained by the great
shipbuding firms in England"
II had heard that Secretary Whitney was very
much pleased with the eXactness with which the
Departments calculations adhered to-" your
upon the construction Of an air ship" =
"In this way. If you were to ask Mr.. Charles II.
Cramp or any of that finn. with Il l their intimate
knowledge Of the strength and weight of metals to
build you the biggest alright cylinder with the
least expenditure of metal strong that it would
allow the air 10 be exhausted, and yet so light in
weight that it would be less than the actual weight
of air pumped out, have you any doubt about their
ability to make such q cylinder? How many times
would they have to experiment to attain the result
asked? l referred to the Cramps because of their
eminence and the daily manner in which they dem
onstrate that greater marvels than we Propose are
actually accomplished"
The scientific details, then, you contend, are al
ready within the range of naval architects skill"
Precisely. 1t becomes, as l said a question of
the displacement of air instead of water, of con
structing cylinder of thinly-rolled metal made
to resist the outside pressure when threefourths
OF the air is exhausted and in having capacity OF
air in weight exceeding the weight of the structure.
1t is, say, only question of naval constructors
skill to do this. The Niagara suspension bridge was
a marvel of engineering triumph twenty-five years
ago. What is it compared with the East river bridge
Of today? The problem of building cylinder of
such capacity rs TO make it not only float, but carry
machinery, is as actually solved as that an oil silk
balloon filed with material far exceeding in light
ness the weight of air. can carry men and ballast
for hours and float over the land hundreds of miles"
The arship, which will probably be designed if
congress encourages the building of it, would have
q lifting force of over one hundred thousand pounds
that is over and above the weight of the ship,
chinery and equipment"
"And what would be the size of this air chamber
to float THIS immense Weight?''
upon all the computations employed, its length
would be about six hundred feet. its diameter about
one hundred and twenty five feet"
''What material would be mainly used in forming
the shell and the hundreds of smaller compart-
ments within, of which you speak?'
''Thin plates of steel suitably braced against eX-
ternal pressure. To this end the shell would be
cylindrical with cones at either end, giving it the
appearance of a double ended cigar, Within would
be air chambers SO constructed to hold eight cubic
metres of air. These in combination would practi-
cally brace the shell and all the compartments. w
know Just what cubic metre of air weighs and as
only three fourths of it is to be exhausted know
definitely how much weight it will float when it is
exhausted
but who is to build such monster cylinder as
you describe?'
THAT is n matter for congress and the engineers
to determine. As 200 tons of metal will be at the
service of the engineers it is question of how the
cradle supporting the cylinder and the cylinder it.
self can be constructed and kept air tight. The
ship equipped will still have when threefourhs of
the air is exhausted carrying capacity of nearly
fifty tons You see what margin there would still
be to add to the weight Of the metal and yet leave
room for q hundred passengers So certain are the
calculations that we are confident that the plans of
iotation can be gradually changed and speed at
tained by taking advantage of air currents which
will make the aerial ship necessity rather than
novelty
1t is understood that q large metal balloon con-
structed on the De Bsusset theory will be made
rs n prap tipallV show its possibilities.