Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-03-03

ed paper over a mold. The result is a
beat perfectly tight and very elastic, with
no seams to need calking. But once pune
tCre or fracture paper skin and the water
soon soaks the fabric at and around the
point of entrance into pulpy mass. Paper
boats seem lighter and stronger than wooden
boats of the same size. and either would
serve in water free from masses of floating
ice. But neither could live in sludge or
brash ice, and neither could endure the
strain of sledging over the rough ice which
We expect to encounter So with skin boats
leather boats, raw-hi1e boats. One after
another. carefully Investigated, fell by the
wayside.
Metal boats came next. Several builders
make admira BILE life-boats of galvanized
iron. Steel boats are very strong. stronger
in ratio to weight. of course, than galvan-
lied iron. But steel boats corrode more
or less in any climate and would be sorry
looking craft after a months use In the
arctcs, where in the summer the atmos-
phere is excessively humid. and where rain,
snow, Sleet or fogS prevail three days out
of five. Obviously steel would not do for
our service.
Amazing Strength of Aluminium.
Then came aluminium. The obiecciols to
It were Is cost and tire more or less cX-
perimental nature of the construction. But
when we found that we could get aluminium
~ per cent pure and 3 per cent copper,with
tensile strength of from 5D.0oO 70 $4,000
pounds per square inch. rather stronger
than the very best iron, and with 81 per
cent the strength of steel. with only one
third The weight of either, neither cost nor
difficulties 81 working up could stand in the
Way. We wanted the hest, and ALUMINIUM
vas Infinitely the best material for our
niue boats. An additional advantage, and
Great one with us, is that aluminium viii
not rust or tarnish. As long IS we are in
the HELD our boats VIII be as bright and
clean as silver, which, indeed, they very
much resemble. iney will not be afInc-@l
r he. all
slight extent. \ sheet of copper and
sheet OF aluminium were suspended outside
The nun OF 4 ship that made 4 long, voyage
to the Indies. on their return IL was round
the copper sheet mad suffered Corr1sion
To the extent Of seEen-thCusandths Of an
inch. While the aluminium had lost only i've
thonsandthS Of an inch. We made careful
tests OF the meal offered US. and found
that sheet 1--WE feet long. Il foot wide and
only three thirty-seconds of an inch in
thickness, weighing about pound and 4
quarter TO the square foot. would sustain
the weight of four men when SUSPENDED
irG1n supports near it's ends. 1t is twice
as stif as a sheet of steel Of the same
weight, and three times stiff as sheet
of galvanized iron.
President Hunt of the Pittsburg Reduc-
ton Company, the largest makers of
alumni in this country. early became in.
terest.d in our project, and cD-operated BY
furnishing just such material was re-
CURED, making special molis and roiliags
Cor our benefit. ana giving advice concern
ing methods of working that has proved
invaluable. We have used both aluminium
with :; per cent OF copper in it and the pure
metal The former Is tougher and stronger
out harder TO work. The pure metal has a
tensile strength. when cold rolled OF about
2',"" pounds per square inch, and. though
| comparatively soft and easy to work has
surprising Stiffness and elasticity.
After .hc surf poat Model
with the mate -fal selected, the next thing
TO be determined was the design. Exrcrt
advice was sought in various directioasana
arctic experience was consiiered through
out a wide range of expeditions and work
The uses to which we were 20 put the craft
were considered first of all. and the de-
signer, Charles e. Dodge OF the construc-
ton bureau of the Navy Department, and
the designer of several successful yachts
was impressed with the idea that va fetv and
endurance were to be placed above ali
things: that we wanted boat fit TO NEE;
the worst possible conditions OF Our pLl-
ney, even To that degree of seaworthiness
which would enable us to cross the cnen
sea that sometimes exists for seysnt,,~liye
or Il hundred miles to the north of Spitz-
bergen in autumn. Nor was he To- over
LOOK the fact that might find il neces-
sGry to land our craft through he surf
either at Spitzbergen or at those now uE-
farther north.
Mr.. Dodge modelled his design very close
~ after the surf boat of the Hfe-saying
service. which has proved itself the best
surf and life-saving craft in the world
1t Is really life boat. but it is called
surf boat in distinction from the heavier
craft OF similar construction which are
called life boats. The service boats are
usually from twenty-five to twenty-seven
feet long, SIX and a half to seven feet beam
and two feet three inches to two feet six
inches depth amidships. The surf boats of
the hfe-saving service are a DEVELOPMENT
not discovery. They We're evolved from
the types of boats in most successful use
along the coasts of Jersey and Long Island
They are made as light as possible, so that
they may be quickly carried or drawn
along the sandy beach to the scene of
wreck. They are still too heavy, and no
one in this country aside from ourselves
Is more interested in these aluminium boats
than Supt. kimball of the life-saving serv-
ice. He is looking for lighter boats and if