158 
Mr. W. L. Dickinson read a paper “ On the Eclipse of the 
Sun. December 21-22, 1870.” This eclipse begins in the 
North Atlantic Ocean ; the line of central and total eclipse 
moving in a south-easterly direction, crosses Portugal a 
little to the south of Lisbon ; passing over part of Spain and 
the Mediterranean Sea, it enters Africa near Oran, and soon 
afterwards attains its extreme southern limit ; the shadow 
of the moon, now moving in a north-easterly direction 
leaves Africa, and crossing the island of Sicily, the south of 
Turkey, the Black Sea, and the Sea of Azof, disappears ; the 
penumbra of the moon, decreasing rapidly, leaves the earth 
with the setting sun in Arabia, The sun will be centrally 
and totally eclipsed at noon, in Lat. 36° 28' N., Long. 5° 1' 
W., a little to the north-east of Gibraltar. 
The Eclipse as seen in England will be partial ; and as 
the sun will be at its greatest southern declination, it has 
not been considered requisite to perform the labour of 
computing from the Elements of the Eclipse. The subjoined 
particulars are the results of a calculation made for the 
Observatory of the late Robert Worthington, Esq., F.R.A.S., 
Crumpsall, near Manchester, from the following numerical 
equations given in the Nautical Almanac. The geogra- 
phical position of the Observatory is Lat. 53° 30' 50 //o 0 N., 
Long. 0 h 8 m 56 S T6 W. 
For any place not far distant from Liverpool, whose 
Geocentric North latitude is l and East longitude X, the Mean 
Greenwich time t of beginning may be computed by 
the formulae, 
cosw = 1 -4612 — [0*2241 2] sin £ + [9*88272' 
£=l h 3 m 43 8 — [3*65845] sin ^ — [312314 
cos (A + 73° 15'-9) 
Contact on sun’s limb, to — 9° 52' 3 from the North towards 
the West. 
cos£cos(A + 142° 33 ; *9) 
sin l — [3*91792] cos l 
Also the Mean Greenwich time t of ending by the formulae, 
cosw- 1*5480— [0*22908]smT+ [9*85616]cos£cos(A + 193° 32 / *0) 
t = 0 h l m 38 s + [3*66027] sin w— [2*72415] sin l— [3*92440] cos l 
cos (A + 111° 58N>) 
Contact on sun’s limb, to + 3° 54L6 from the North towards 
the East. 
Eclipse begins Dec. 21, 23 h 5 m 22 s ] 
Greatest Phase „ 22, 0 21 3 r 
Eclipse ends „ 22, 1 36 57 ) 
Mean Time at 
Greenwich. 
