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the authorities in France conclude that he had defected with who-knows-what
consequences for his family back in Paris? Lacking the knowledge that everyone
in Paris had come to the obvious conclusion that he was imprisoned in Spain,
Méchain made arrangements to depart to neutral Italy, and left for Genoa in June.
BACK IN PARIS, Delambre remained under suspicion. He had returned to his house
and was permitted to enter only when accompanied by local commissaries who scruti-
nized every paper in the house. The officials paid great attention to a certificate of his
membership to the Royal Society of London and to papers covered with what might be
calculations or enciphered secrets. At the Observatory, Cassini IV bitterly opposed the
involvement of the new revolutionary government in observatory affairs and was
affronted by the execution of King Louis XIV in January 1793. Cassini was betrayed
by three assistant astronomers drunk on the revolution with the supposed equality of
their knowledge of science to his. They demanded co-authorship of papers which they
had all worked on under Cassini's direction and not mere acknowledgement.
The Observatory was reorganized on egalitarian lines. Cassini was demoted and
his salary halved, while the three assistants were promoted to be at his level and rate
of pay. One of them was made the first director under a new rotating arrangement
for the position. In protest Cassini resigned, was ultimately evicted and his scien-
tific work seized. When he protested again, he was imprisoned and faced with the
suggestion by one of the three assistants (Alexandre Ruelle) that he be sent to trial
by the Revolutionary Tribunal. Cassini escaped trial and what would have been the
near certainty of the guillotine but was imprisoned for 8 months. He retired from
scientific work to his château and the comparative safety of local politics. He spent
his old age writing polemics justifying his own position and defending the scientific
reputation of the family.
The three assistant astronomers, now Professors, remained working at the Observatory.
Ruelle was discovered to have lied about some solar data, fraudulently concocted from
theory and not from observations. Ruelle fell from favor and was imprisoned. The two
remaining former assistants invited Delambre to join them as a Professor at the
Observatory, but he wisely continued to stay out of the public eye remaining to work at
his country manor.
In June 1795 the Observatory was put under the control of a newly created state
body, the Bureau of Longitudes, and there was yet again another reorganization. With
his impeccable republican credentials, Joseph-Jérôme Lalande was appointed Director.
The meridian project was restarted in a calmer political atmosphere, and Delambre
was asked to take it up again serving under the title of
Astronomer of the War
Department
. When Delambre left the city in June 1795 and headed south to the most
southern extent of his northern half of the meridian in Bourges, he must have felt glad
to have kept his head and to have left behind the terror of the past two years in Paris.
Delambre still had practical difficulties to overcome, such as convincing inn-
keepers to accept the letters of credit that the Government had given him with
which to pay for supplies, but he was able to contemplate completing his scientific
work. He linked Bourges, Orléans and the Sologne region and headed back north
to Dunkerque to measure its latitude and compare it with Méchain's measurement
of the latitude of Montjuïc.
