PRESIDENTIAL ADDRESS. V/A | 
from the primary than any of the other previously known 
five satellites. Its photographic magnitude was fourteen, 
so that it is fainter than the fifth, which was discovered 
by Barnard in 1892. 
Seventh Satellite of Jupiter._A telegram containing a 
message from Campbell was received stating that the 
previously announced discovery of a seventh satellite to 
Jupiter had been confirmed ; it was discovered by Perrine 
with the Crossley refiector at the Lick Observatory. The 
Astronomer Royal of England exhibited and explained 
some photographs of the sixth and seventh satellites of 
Jupiter, obtained with the 30-inch reflector of the 
Thompson equatorial of Greenwich. The results of the 
provisional measures of the photographs, and _ their 
comparison with the angles and distances given by 
Dr. Ross’s ephemeris, the dates, and exposures are given 
in No. 1 VOL. Lxvi of the Monthly Notices. The exposures 
for the seventh satellite varied from 17 to 177 minutes. 
Solidification of the interior of a Planet.—_MM. Loewy 
and Puiseux have a short note concerning the extensive 
enquiry prosecuted by the authors into the evidence 
bearing on the physical state of the lunar crust as 
determined from a minute study of the features of the 
moon’s surface on the photographs taken with the 
equatorial Coudé at the Paris Observatory. Starting with 
a short reference to the views of Kelvin, Darwin, King, 
and Barns, advocating the view of the earth’s solidification 
as opposed to those of Suess and Lapparent, who think it 
to consist merely of a thin solidified crust enclosing a 
liquid viscous interior, the evidence supplied by the lunar 
formations is discussed and considered to favour the latter 
view. As evidence supporting the idea of gradual 
solidification from the surface inwards, the successive 
terrace formation seen in many lunar craters and seas is 
