Simon Newcomb,
1911 Encyclopædia Britannica, Volume 20…
(1911)
“ In astronomical practice the masses of the planets are commonly expressed as fractions of the mass of the sun, the latter being taken as unity. When we know the mass of the earth in gravitational measure, its product by the denominator of the fraction just mentioned gives the mass of the sun in gravitational measure. ”
Simon Newcomb,
1911 Encyclopædia Britannica, Volume 20…
(1911)
“ The difficulties in the way of solving it are very great, and up to the present time the best authorities are not agreed as to the result, the effect of half a century of research having been merely to reduce the uncertainty within continually narrower limits. The mutations of opinion on the subject during the last fifty years have been remarkable. Up to about the middle of the 19th century it was supposed that transits of Venus across the disk of the sun afforded the most trustworthy method of making the determination in question ”
Simon Newcomb,
1911 Encyclopædia Britannica, Volume 20…
(1911)
“ From the meridian observations of the same planets made for the purpose of controlling the elements of motion of the planets Auwers found π=8.806". In 1898 the remarkable minor planet Eros was discovered, which, on those rare occasions when in opposition near perihelion, would approach the earth to a distance of 0.16. On these occasions the actual parallax would be six times greater than that of the sun, and could therefore be measured with much greater precision than in the case of any other planet. Such an approach had occurred in 1892, but the planet was not then discovered. ”
