COLLECTION MUSEUM VICTORIA
T
O AN UNTRAINED EYE, the glass plate
resembles a dirty tile covered with tiny black
spots – as if an ink-filled paintbrush had been
gently flicked across its surface. But in fact the plate
is a piece of the night sky – the glass-plate negative
from a photograph taken over a century ago. Each
black speck – shown on these pages –is a single star.
There are thousands of such plates – the precious
residue of one of the most ambitious international
astronomy projects undertaken in the 19th century.
The goal was to use photography to map the entire
sky and create a complete record of the stars, known
as the Astrographic Catalogue (AC), and a separate
project of printed images called the Carte du Ciel.
Originally estimated to take only a few years,
the project would span more than seven decades in
Australia. Behind the scenes were female “human
computers” who diligently measured and calculated
the position of tens of thousands of stars, whose work
has remained mostly unnamed and unrecognised for
decades (see p 39).
Toner Stevenson was manager of Sydney
Observatory in 2004 when she first saw the glass
plates with observatory curator Nick Lomb. Each was
160mm^2 , with a curved corner at bottom left. She’d
been reading about the AC for her doctoral thesis
and had come across a sentence saying that the star
measurements were why the project took so long.
The search for an answer led her to Macquarie
University’s library and a basement lined withCirca 1900, an astrographic
measurer uses the “Repsold”
micrometer – measuring
machine – at Melbourne
Observatory to catalogue
the stars of the southern
hemisphere. One of the
glass plates is shown on
these pages.For seven decades, the world worked to map the heavens –
a massive endeavour that ran from the 19th century to the
era of manned space flight, taking in two world wars and
vast social change. Here, we explore Australia’s role in the
project and the lives of those who measured the stars: the
“lost women” of Australian astronomy.
shelves stocked with thousands of cardboard boxes- each containing up to a dozen glass plates in paper
covers, where they had rested for 20 years.
When Sydney Observatory stopped being a
research station, Macquarie University astronomer
Alan Vaughan volunteered to find a place to store
the thousands of plates in its collection, and the
University signed an agreement with the Museum of
Applied Arts and Sciences, which currently operates
Sydney’s Powerhouse Museum and Museums
Discovery Centre, as well as the Sydney Observatory.
Each glass plate was wrapped in a paper cover
with notes and observations; Vaughan was their
caretaker from 1986. He recalls finding a 1910
cover with the notation “Halley’s Comet”. The glass
plate inside had an image of the comet itself – a dark
brushstroke across the surface rendered as it streaked
across the sky.
The collection included the original logbooks and
catalogues, which preserved all the data of exposure - including date, time, weather, observer, length of
exposure, the relative ascension and declination (co-
ordinates) and the plate number.
“I thought: This is an incredible story because this
is the sky captured during a single epoch, because most
of the photographs were taken over 20 years from
1895 to 1915,” says Stevenson, who now manages the
University of Sydney’s School of Philosophical and
Historical Inquiry. “So it was capturing something
we could never capture again.”
By IVY SHIH
Issue 86 COSMOS – 35ASTROGRAPHIC CATALOGUE