40 AUSTRALIAN SKY & TELESCOPE November | December 2017
J-M. KOLLAR / PARIS OBSERVATORYTSURVEYING TOOLS Lacaille
used this large sextant, with a
small-aperture telescope attached
to its righthand side, for his
geographic work. For astronomical
measurements in the constant wind,
he got better results from a smaller
telescopic quadrant on a fixed
meridional mounting.index,andissuedareportontheappearanceoftheComet
of 1759, now called Halley’s Comet. He wrote an early draft
of his travel memoirs,Journal Historique.He also managed
toreduce1,942ofhis9,766starpositionstostandard,
equinox-1750 right ascensions and declinations, at a time
whenthemathswasdonewithpaperandpencil.Thomas
Henderson (Royal Observatory, Edinburgh) and Francis Baily
(FRAS)compiledtherestinEdinburghinthe1840sand
publishedthefulllistin1847asA Catalogue of 9766 Stars in
the Southern Hemisphere.
Lacaille dreamed of returning to observe the southern
heavens, but he never got the chance. Twenty-seven years of
hard work and long nights at the telescope took their toll. In
early 1762, symptoms he suffered in South Africa returned:
headaches, nosebleeds, fever and digestive problems. Dutch
doctors at the Cape had helped Lacaille, but Parisian doctors
could not. He died on March 21, 1762 at the age of 49.Legacy
It was said of Lacaille that he made more observations and
calculations than all his peers combined. That may be true.
Lacaille was no innovative thinker like Isaac Newton or
Pierre-Simon de Laplace, and he was not given to speculating in public about the nature of what he observed, as William
Herschel did a few decades later. Instead, Lacaille was a data
collector of the highest order at a time when the burgeoning
sciences required exactly that. His results enhanced
navigation, geodesy and astronomy. And they set the stage
for the mid-19th century astronomical work in South Africa
by John Herschel and Thomas Maclear.
Lacaille could have accomplished even more. But he
suffered the great regret of many northern stargazers
who travel to the Southern Hemisphere — he should have
brought a bigger telescope. John Herschel, who transported
an 18¼-inch reflector to South Africa in 1833, discovered
and catalogued some 1,700 deep sky objects in the southern
skies. Had Lacaille been better equipped, he would surely
have earned credit for many of them nearly a century earlier.
Still, Lacaille is often called the ‘father of southern
astronomy,’ especially in South Africa, where he continues
to be held in high regard. Unlike the Herschels or Charles
Messier, he’s not well known generally, perhaps because he
caused little controversy, shunned fame, kept to himself and
died relatively young. But fame was not his goal. Indeed,
as his recent biographer David S. Evans said of Lacaille, he
“lived for science and nothing else. In none of the accounts
does he ever appear as a definite personality; he has few
friends and no emotions. He seems a man without a private
life who appears to pour forth the flood of his researches and
disappears into an obscurity in which those researches are at
once the only light and the only memorial.”BRIAN VENTRUDO is a writer, scientist, and amateur
astronomer. He publishes the popular astronomy website
CosmicPursuits.com, with articles for science buffs and
stargazers in both hemispheres.OCTANSHOROLOGIUMPICTORNICOLAS-LOUIS DE LACAILLE