412 
P0PULAE SCIENCE EEVIEW. 
direction, but is more tban twice the length of the American 
zone. Of all the observed falls of aerolites, 90*9 per cent, 
have taken place within this area, and were also concentrated 
in that half of the zone which extends along the Atlantic.” 
On reference to a map, it will be seen that in the western 
continent, the so-called zone is simply confined to the United 
States — the most densely inhabited portion of America. In 
like manner the eastern zone leaves out the whole of desert 
Africa, Lapland, Finland, the chief part of Russia, with an 
average of thirty-two inhabitants to each square mile ; Sweden 
and Norway, with only seventeen per mile, whilst it embraces 
all the well-peopled districts of central Europe, most of which, 
like England, are able to count between three and four hun- 
dred persons to every mile of their territory. In fact, Pro- 
fessor Shepard^s statement may almost be resolved into a plain 
question of population, for were an aerolite to fall in the midst 
of a desert, or in a thinly-peopled district, it is needless to 
point out how few the chances are of its descent being ever 
noticed or recorded. That innumerable aerolites do fall 
without attracting any attention, is clearly proved by the 
number of discoveries, continually taking place, of metallic 
masses, which from their locality and peculiar chemical com- 
position, could only be derived from some extra-terrestrial 
source. The great size also of many of these masses entirely 
precludes the possibility of their having been placed by 
human agency in the positions they have been found to 
occupy — sometimes on the surface of the earth, but just as 
frequently buried a few feet in the ground. 
Thus the traveller Pallas found, in 1749, at Abakansk, in 
Siberia, the mass of meteoric iron, weighing 1,680 lb., now 
in the Imperial Museum at St. Petersburg. Another, lying 
on the plain of Tucuman, near Otumpa, in South America, 
has been estimated, by measurement, to weigh no less than 
33,600 lb., or about 15 tons ; and one added last year to the 
splendid collection of meteorites in the British Museum 
weighs rather more than 3 \ tons. It was found at Cranbourne, 
near Melbourne, and was purchased by a Mr. Bruce, with a 
view to his presenting it to the British Museum, when, 
through some misunderstanding, it was discovered that one- 
half of it had been already promised to the Museum at Mel- 
bourne. In order, therefore, to save it from any such mutila- 
tion, the trustees of our National Museum acquired and 
transferred to the authorities of the Melbourne collection a 
smaller mass which had been sent in 1862 to the International 
Exhibition. It weighed about 3,000 lb., and had been found 
near Melbourne in the immediate vicinity of the great me- 
teorite. The latter was then forwarded entire to London. In 
