1860-70] ROYAL ASTRONOMICAL SOCIETY 163 
is less strong than that to be derived from other physical 
phenomena. 
Admiral Russell Henry Manners [1800-70] was elected President 
in 1868. He had retired from active service in 1849. He joined the 
Society in 1836 and was one of the Secretaries for ten years, 
1848-57; he then became Foreign Secretary, and held that post 
for ten years, till his election as President. 
Manners delivered the address in 1869 on presenting the Gold 
Medal of the Society to Stone, for his rediscussion of the Transit 
of Venus in 1769 and his other contributions to Astronomy. By 
reason of illness, Manners was unable to give the address on the 
award of the medal to Delaunay in 1870 February, and he died on 
May 9. As has been stated on an earlier page, Adams delivered 
the address on Delaunay’s work. 
E. J. Stone [1831-97] was educated at King’s College, London, 
and in 1856 went to Queens’ College, Cambridge. He graduated 
as fifth Wrangler in 1859 and became a Fellow of his College. 
In i860 he became First Assistant at the Royal Observatory, and 
held the post for ten years, until he was appointed to the Cape 
Observatory in 1870 on the resignation of Sir Thomas Maclear. 
On Main’s death in 1878, Stone was appointed Radcliffe Observer, 
and held the post until the day of his almost sudden death in 1897. 
He was one of the Secretaries of the Society from 1866 till 1871, 
Huggins being his fellow Secretary. 
Stone’s work on the solar parallax was the chief theme of 
Manners’s address. Airy had in 1854 and 1857 taken steps to 
move astronomers to a realisation of the need to revise Encke’s 
value 8"-57, derived from the observations of the 1761 and 1769 
Transits of Venus, which had been held in general acceptance from 
1824 U P to the beginning of this decade. Hansen had also derived 
from his investigations of the moon’s motion a conviction that 
Encke’s value was too low ( M.N. , 15 , 9), and had himself deduced 
a value 8"-92 ( M.N ., 24 , 8). Again Le Verrier had found in 1858 
from his researches that a value of 8"-95 was indicated. Yet again 
Foucault in 1854 had measured the velocity of light and found a 
value 185,287 miles/sec. (298,187 km./sec.), considerably less than the 
value deduced by Fizeau from his avowedly preliminary experiment 
in 1849 (194,663 miles/sec. or 313,274 km./sec). Observations of 
eclipses of Jupiter’s satellites were taken as indicating a value of 
about 192,500 miles/sec. All these lines of research called for a 
revision of the value of the sun’s distance from the earth. Hence 
Airy’s eagerness for a worthy attack on the problem, and the 
readiness with which astronomers responded to the call. Stone’s 
reductions of observations of Mars made in 1862 at Greenwich,