The EconomistFebruary 10th 2018 Science and technology 732 The searchers are not searching blind.
They know, from mining records dating
from the mid-1800s, that there is lithium in
Cornwall’s rocks. Those records tell of un-
derground springs containing salts of lithi-
um—at that time quite a recently discov-
ered element. Back then these springs were
seen, at best, as curiosities, and at worst as
flooding risks, because there was then no
market for the metal. Today, there is. In par-
ticular, lithium is the eponymous compo-
nent of lithium-ion batteries. These power
products ranging from smartphones to
electric cars, and are being tested as a
means of grid-scale electricity storage
which could make the spread of renew-
able energy much easier. No surprise, then,
that prices have been rising. In 2008 a
tonne of lithium carbonate cost around
$6,000. Now it would set you back more
than $12,000.
This price is less a reflection of lithium’s
overall scarcity than of the rarity of good,
mineable deposits oflithium compounds.
(Like most metals, it does not occur natural-
ly in its elemental form.) At the moment,
the best workable supplies are in Australia,
South America and China. But mining
companies are eager to discoverothers. Dr
Rossi’s team intend to use satellite cam-
eras, both optical and infra-red, and also
satellite-borne radar, to look for mineral
formations caused by hot liquids reacting
with existing rock, and for rock fractures
that could act as channels for lithium-bear-
ing brine. They will, as well, record anoma-
lies in vegetation that might be the result of
lithium-rich soils, or of hot springs that
might contain the element.
The acid test, though, will be to drill
where the map thus generated suggests.
One group member is ready for that. Cor-
nish Lithium is a newly created firm that
has already secured various mineral rights
to explore for lithium, and to extract it.
This extraction would not, however, be
carried out in the way that it is in the Ataca-
ma Desert of Chile, where one of the larg-
est lithium mines in the world prepares
lithium salts by drying out vast lakes of
brine in the sun. As tourists to Cornwall
know all too well, the sun is not to be relied
on there. Instead, Cornish Lithium says it
will use special filtration techniques called
reverse osmosis and ion-exchange to ex-
tract and purify lithium compounds from
any brine that it finds.
If the experiment in Cornwall proves a
success the system could, Dr Rossi reckons,
be used to search for lithium in other
places. One target would be Chile’s neigh-
bour, Bolivia, which is reckoned to have
some of the biggest butstill largely un-
tapped deposits oflithium in the world.
Any find in Cornwall is likely to be tiny by
comparison. But if such a find were made
there would be a nice symmetry to it, as
one of the world’s oldest mining centres
became also one of its newest. 7
J
ULY 2nd of last year marked the 80th an-
niversary of the disappearance of Ame-
lia Earhart, a pioneering aviatrix (pic-
tured above), and her navigator Fred
Noonan over the Pacific Ocean, as they at-
tempted a circumnavigation of the globe
in a twin-engined Lockheed Electra mono-
plane. The many theories about the pair’s
demise, aired once more on that occasion,
fall into two broad groups: they crashed
into the sea and drowned, or they crashed
onto Nikumaroro, a remote island, where
they perished from hunger. An American
forensic anthropologist has new evidence
that greatly increases the likelihood of
their having suffered the second fate.
Nikumaroro, one of the Phoenix Is-
lands, is an inhospitable place and was un-
inhabited at the time of the Electra’s disap-
pearance in 1937. Three yearslater, though,
a working party found a human skull and
partial skeleton there. Nearby was a part of
a shoe they judged to be a woman’s, and a
box manufactured in around 1918 that was
designed to contain a sextant. The bones
were removed to a medical school in Fiji
where David Hoodless, a British doctor
and anatomy teacher, measured them and
concluded that they had belonged to a
stocky, middle-aged male.
At some point the boneswent missing,
so the mystery of the Nikumaroro cast-
away rests on Hoodless’s measurements
and on the state of forensic anthropologyin 1941. Without the bones themselves it is
hard to assess the reliabilityof the mea-
surements. But Richard Jantz, a former di-
rector of the University of Tennessee’s Fo-
rensic Anthropology Centre, points out in
an article reviewing the evidence, just pub-
lished in Forensic Anthropology, how prim-
itive the discipline was at the time.
Hoodless used formulae developed by
a 19th-century statistician, Karl Pearson, for
calculating stature from bone length, and
concluded that the castaway was five feet
five-and-a-half inches (1.66 metres) tall.
Pearson’s formulae are now, though, wide-
ly acknowledged to underestimate height.
Hoodless also used three indicators of sex:
the ratio of the circumference of the femur
to its length; the angle between the femur
and the pelvis; and the subpubic angle, be-
tween two bones in the pelvis, which is
larger in women than in men.
Of those three indicators, only the sub-
pubic angle is still considered valid, and in
his notes Hoodless did not divulge the rela-
tive weight he gave to each. Even today,
says Dr Jantz, an experienced forensic an-
thropologist making a sex assessment on
the basisof this angle alone will not get it
right all of the time—and is obliged to ex-
press his conclusion in terms of probabili-
ties. Hoodless observed that the bones
were “weather-beaten”, damage Dr Jantz
thinks was more likely to have been
caused by scavenging crabs, and which
might also have thrown Hoodless’s mea-
surements off.
If Hoodless was right, the remains
could not have been those of the slender
Earhart, whose driving and pilot’s licences
gave her height as five foot seven and five
foot eight respectively. Nor could they have
been Noonan’s, since he was a quarter of
an inch over six feet tall. But Dr Jantz con-
cludes that in 1941, with the tools at his dis-
posal, right is something Dr Hoodless was
unlikely to have been.
Dr Jantz also describes some new re-
search into the matter. Americans of that
era differed morphologically from their
modern counterparts, so he compared
Hoodless’s measurements to those of the
skeletons of 2,700 white Americans who
died between the 19th and mid-20th centu-
ries. He included measurements of Ear-
hart’s own bones calculated from photo-
graphs of her. He concludes that her bones
more closely resembled the castaway’s
than do 99% of the reference sample.
That finding might be enough to con-
vince those who have until now sup-
ported Hoodless’s conclusion. But it is un-
likely to silence the conspiracytheorists
who continue to circle Earhart’s disappear-
ance. The truth may never be known fully.
But even if those who claim she drowned
succeed in explaining away the resem-
blance Dr Jantz has unearthed, another
mystery awaits an answer. If the castaway
was not Earhart, who was it? 7Amelia EarhartMystery solved?
A skeleton found in 1940 may, after all,
have been that of the lost aviatrix