12 AMERICAN MUSEUM GUIDE LEAFLETS 
Meteoritic masses are almost certainly extremely cold during their 
existence in outer space, but when they come into the earth’s atmosphere 
friction with the air raises the temperature of the surface to the melting 
point, producing a great amount of dazzling light as well as superficial 
heat. In spite of this surface fusion, it is highly probabie that the dura- 
tion of the aérial flight of a meteorite is so short that in many cases the 
interior does not become even warm.’ 
The rapid heating of the exterior and the differences of temperature 
between different parts of a meteorite often lead to its rupture before 
it reaches the ground. ‘This is particularly the case with stone meteo- 
rites, the iron meteorites being tough enough usually to withstand the 
fracturing agencies. Most of the meteorites which have burst have 
furnished only two or three fragments, so far as known, but a few have 
furnished many, while there have been found 700 pieces of Hessle, 1000 
pieces of Forest City, several thousand each of Knyahinya and I, Aigle, 
and about one hundred thousand each of Moes and Pultusk. The 
name “stone shower” has been appropriately given to the falls com- 
prising many individuals. ‘‘Iron showers” from bursting siderites are 
much rarer than the stone showers, only six are known to have occurred, 
among which Canyon Diablo leads, several thousands of fragments of 
this famous fall having been found. 
The breaking up of a meteorite is accompanied by an explosion or 
series of explosions, and often these are startling in their sharpness and 
intensity, when they occur near the earth. Forest City, 268 pounds of 
which have been found, just before falling burst in a series of explosions 
which were heard over an area two hundred miles in diameter. ‘There 
were three distinct detonations connected with the fall near Butsura, 
Bengal, which were heard at Goruckpur sixty miles away, although the 
meteorite was a small one, less than fifty pounds of it having been found. 
‘The occurrences at Krakhut, L’Aigle and Ensisheim have already 
been mentioned. 
Chemical Com position. 
Some forty one elements, four of which are gases, are said to oceur 
in meteorites, but several of these may be regarded as doubtful. ‘The 
' See also page 18. 
