 For the 1769 transit , scientists traveled to Tahiti , Norway , and locations in North America including Canada , New England , and San José del Cabo ( Baja California , then under Spanish control ) ; . The Czech astronomer Christian Mayer was invited by Catherine the Great to observe the transit in Saint Petersburg with Anders Johan <unk> , while other members of Russian Academy of Sciences went to eight other locations in the Russian Empire , under the general coordination of <unk> <unk> . The Hungarian astronomer Maximilian Hell and his assistant <unk> <unk> traveled to <unk> , Norway , delegated by Christian VII of Denmark . William Wales and Joseph <unk> made their observation in Hudson Bay , Canada , for the Royal Society . Observations were made by a number of groups in the British colonies in America . In Philadelphia , the American Philosophical Society erected three temporary observatories and appointed a committee , of which David <unk> was the head . Observations were made by a group led by Dr. Benjamin West in Providence , Rhode <unk> and published in 1769 . The results of the various observations in the American colonies were printed in the first volume of the American Philosophical Society 's Transactions , published in 1771 . Comparing the North American observations , William Smith published in 1771 a best value of the solar parallax of 8 @.@ 48 to 8 @.@ 49 arc @-@ seconds , which corresponds to an Earth @-@ sun distance of <unk> times the Earth 's radius , about 3 % different from the correct value . 
