Venus: The Transit of 1874

Abstract

Nobody pretended that the results obtained from the 18t^h century transits of Venus were satisfactory. There was too much spread in the observations. Encke’s derived value for the distance of the Sun — 95 370 000 miles — was generally believed to be too great (as indeed it was, but this was not Encke’s fault; he had done his best with the material available to him). Other methods, not involving Venus, indicated that the real distance was more like 93 000 000 miles, but considerable uncertainty remained, and much was expected from the transits of 1874 and 1882. After all, telescopes and astronomical techniques had been improved beyond all recognition since 1769.