Note 1 — Chapter I
Reading edition
Periodically the planet Venus passes so exactly between our Earth and the sun that the planet is outlined against the sun's disc and may be seen crossing it slowly as a small, black dot. These events, known as transits, are quite infrequent, occurring in duos of eight years, separated by longer intervals alternating between 105 and 122 years.
Transits of Venus occurred in 1874 and 1882, in 2004 and 2012 A.D. That observed by Dr. Gary Lane and Flick Muldoon was apparently the transit of June 11, 2247 A.D.—Ed.