Iron heliometer tower, which served as an observatory, and housing for instruments, including powerful telescopes, used in viewing the December 6, 1882 Transit of Venus in Aiken, South Carolina. Theobservatory was built in two sections, each twelve feet in diameter, so they could revolve independently of each other. These sections were covered with canvas.
December 6, 1882 is the day the planet Venus was to have transited, or crossed between, the sun and the earth. Scientists had assembled in Aiken hoping to measure the distance from the earth to the sun during this transit. Although other sites were also selected in the United States and abroad, Aiken was favored as an ideal site for viewing this phenomenon because of the likelihood of fair weather here. Dr. Julius Franz, professor of astronomy at a German university and chief astronomer at the Royal Observatory in Koenigsburg, Germany, led the expedition. There had also been several other eminent scientists present in Aiken in October of 1882, when the groundwork was laid for the December transit viewing.
A site was selected in the north end of the town of Aiken on part of Mr. Henry Smith's estate, between Barnwell and Edgefield Avenues from Laurens to Newberry. This site was far enough from the railroad so that the sensitive instruments needed for the viewing would not be vibrated when trains passed through.
Varying accounts of the success of the viewing exist. One states that a heavy rain lasted from midnight December 5th until about sunrise the next morning. At noon the sun appeared, and three sets of heliometer measurements were completed. An estimate of the measurement was agreed to be approximately 93,000,000 miles, which is close to later estimates of 92,957,000 miles.
The next Transit of Venus is predicted to occur in 2004.