SCIENTIFIC SUMMARY. 
427 
From these results Professor Busk draws the following conclusions. The 
rock of Gibraltar, after undergoing its last changes, but while still united to 
Africa, was covered with trees, and harboured numerous large mammals. Some 
of these species, such as the elephant and rhinoceros, are now extinct ; and 
others, such as the spotted hyaena, now exist only in the southern part of 
Africa. The leopard and Felis coligata are no longer found in Europe, but 
the lynx and Spanish ibex still inhabit the mountains of Spain. The 
entire fauna exhibits purely African affinities, and the author infers from the 
occurrence of Elephas antiquus, Rhinoceros hemitcechus , the hyaena and the 
cats at this southern point of Europe, unmixed with northern forms, that 
those species probably made their way northwards through the isthmus 
formerly connecting Europe and Africa at this point. 
METEOROLOGY. 
The Heed Evolved by Meteorites in Traversing the Atmosphere. — M. Govi, 
in a note presented to the French Academy of Sciences (“ Comptes rendus,” 
Aug. 20), discusses this question. M. Schiaparelli has demonstrated that, 
in order to calculate the loss of velocity of a body penetrating the atmo- 
sphere, it is not necessary to know the law according to which the density 
of the air varies in the different strata of the atmosphere traversed, but only 
the barometric pressure at the two extremities of the course, or (what comes 
to the same) the weight of air displaced by the body the initial velocity of 
which is known. M. Schiaparelli has also ascertained that the velocity of 
meteorites varies between 16,000 and 72,000 metres per second. Taking 
50,000 metres per second as an average velocity, M. Govi calculates that a 
meteorite penetrating vertically into the atmosphere with this initial 
velocity would have a velocity of only 28,968 metres per second on reach- 
ing the point where the barometric pressure is one millim., 5,916 metres at 
ten millims., 506 metres at 100 millims., and five metres per second at the 
level of the sea. Taking these figures as indicating the lowest effect pro- 
ducible on a meteorite by the resistance of the air, M. Govi calculates that the 
number of calories corresponding to the loss of vis viva of a meteorite of 14*66 
kilogr. reaching the stratum of air where the pressure is scarcely one millim., 
would be 2,921,317, which would more than suffice to explain all the phe- 
nomena of light and heat, and all the mechanical effects produced by the 
penetration of a meteorite into the highest strata of our atmosphere. Even 
at an elevation where the barometric pressure is only 0*001 millim., the me- 
teorite in question might already have developed 6,413 calories, and have 
become visible. This, according to M. Govi, explains the enormous eleva- 
tion of some meteorites the distance of which from the earth has been 
measured. 
Sun-spots and Storms. — Mr. Henry Jeula, of Lloyd’s, has lately written to 
the “ Times ” indicating that there appears to be some connection between 
the prevalence of sun-spots and the number of wrecks posted annually in 
Lloyd’s u Loss Book,” and that this may constitute a further link in the 
evidence connecting sun-spots with the phenomena of weather. He derives 
his data from two complete cycles of eleven years each, extending from 
f f 2 
