Astronomers Royal, scientific advice and engineering

This evening, the Astronomer Royal,
Lord Rees , will weigh into the debate
about climate change and
geoengineering in an address at the
British Science Festival.
Finding such fixes, as well as more
efficient forms of alternative energy,
may well be problems focused on by
the new challenge prize that Rees has
helped set up. That he, as Astronomer
Royal, will be judging what has been
called a new 'Longitude Prize' , seems
appropriate, but the innovations
under consideration may be a long
way from his own field of astronomy
and cosmology.
Today the post of Astronomer Royal is
honorary. It means simply, as Alok
Jha's article on Rees's speech suggests,
that he is "one of Britain's most
senior scientists". Like a Chief
Scientific Advisor, or the head of a
scientific society, the Astronomer
Royal can be expected to give all sorts
of opinions about science and science
policy, straying at least occasionally,
if they wish, well beyond their area
of research.
Was it always like this? Yes and no.
Until the 1970s the post of
Astronomer Royal was synonymous
with director of the Greenwich
Observatory (at Greenwich ,
Herstmonceux and then Cambridge).
Before the 19th century, the AR was
also an active observer, in fact only
one of two observers in the
institution.
Nevertheless, Astronomers Royal
were often called upon to make
judgements and offer advice in areas
that did not relate to making
observations or managing an
observatory. Because the Royal
Observatory was funded by
government, being under the
administration of first the Board of
Ordnance and then the Admiralty,
there was potential for them to be
asked to consider a whole range of
technical and scientific issues.
For much of the AR's history, the
most obvious place in which this
happened was the Board of Longitude.
While many of the ideas under
consideration were astronomical
(involving knowledge of
astronomical theory, mathematics,
optics and instrumentation), others
were based on geomagnetism or, of
course, horology. Understanding
clocks and timekeeping was essential
to astronomy, but the specifics of
horological theory and manufacture
would have been beyond the AR's
experience.
ARs also advised on areas like
cartography, instrument design and
weights and measures, that involved
techniques closely allied to
astronomy. But they were also asked
to consider a wide range of fields of
interest to the Admiralty and other
branches of government, simply
because they ended up being their
available scientific expert.
One of the ARs who most obviously
became the government's go-to
scientific and technical guy was
George Airy , who was in position
from 1835 to 1881. Airy covered a
great deal of ground, intellectually
and practically. Unlike all his
predecessors he was not much
involved with daily observations and
he had a significantly larger
workforce at the Observatory, onto
which observation, calculation and
even management could be delegated.
Airy, for example, did a considerable
amount of work on the effect of iron
ships' hulls on compass use and
design. He also advised, like many
other ARs, on education and he was
involved in the organisation of the
Great Exhibition. He was, perhaps
most intriguingly, called in to advise
the Great Western Railway on track
gauges and the engineer Thomas
Bouch about the pressures that might
be exerted by wind on the planned
rail bridge crossing the Forth.
That latter advice got him into
trouble. It was first applied by Bouch
to the Tay Bridge and, when that
collapsed in 1879 , Airy was called in
by the enquiry. He claimed that his
advice had been specific to the
circumstances of the Forth and the
design for that bridge (which was now
speedily discarded). The enquiry
agreed, suggesting that Bouch had
"must have misunderstood the nature
of [Airy's] report".
Airy did know quite a lot about
engineering. He was, apart from
anything else, closely involved with
the design of large instruments and
their mounts at Greenwich. Times and
the nature and range of expertise
have changed considerably since the
19th century, however. Lord Rees is
not an Astronomer Royal who can
offer specific or technical
engineering expertise, rather he is
calling for research and funding.
Whether or not you agree with his
statements is a different matter.