Transit of Venus

[RICHARD ROMEO]

>From History of Armagh Observatory 
(http://star.arm.ac.uk/history/history.html)

The Transit of Venus and the Voyages of Captain Cook

As knowledge of the motions of the planets improved it became possible to 
make more precise
predictions for the future. In 1769 it was predicted that the planet 
Venus would transit across the
face of the sun as viewed from the Earth. It was realised that this rare 
event would provide a
unique opportunity to determine the basic unit of the solar system, the 
distance from the earth to
the sun, (called the Astronomical Unit) provided it could be observed 
from several stations
around the world. 

The Royal Society commissioned Captain Cooke to voyage to the Pacific to 
observe this event
from the South Seas and to this end he carried with him an astronomer. It 
was during this voyage
that Cooke annexed Australia. (Drawing by Cooke of transit of Venus). 

Observations of the transit were also made by King George III from his 
new observatory at Kew,
built specially for the purpose. The telescope by Short used by George 
III for this historic
observation was presented to Armagh Observatory by Queen Victoria. A 
clock, by Shelton of
London, was used by George III to determine the exact time of the 
apparition. 

The transit of Venus in 1769 was also observed from Ireland using special 
instruments brought
from London for the purpose. They were carried out at Cavan, a townland 
near Strabane, by
Charles Mason (of Mason-Dixon Line fame). 


Richard Romeo
Coordinator of Cooperating Collections
The Foundation Center-NYC
212-807-2417
rromeo at fdncenter.org