METEORITE COLLECTION—HANDBOOK AND CATALOGUE, 15 
hind the advancing mass in the form of an igneous globe, making a 
flame shaped like that of a candle, and under the intense heat a large 
portion of the mass is dissipated into a vapor or smoke. The heat 
moreover, causes cracking of the surface (Linn Co., 255, Dona Inez, 
193) and an unequal expansion of the mass which bursts it, often 
with explosive violence. 
In spite of the high temperature to which its surface is raised, 
however, the substance of the meteorite is so poor a conductor that 
its interior is often scarcely heated at all. When picked up immedi- 
ately after their fall, therefore, meteorites are often scarcely more 
than blood warm and in one remarkable instance, that of the Dhurm- 
sala (275) meteorite, the fragments were’so cold as to benumb the 
fingers of those who collected them. This is perhaps the only in-. 
stance known in which the cold of space has become perceptible to 
human senses. 
| Another effect of the passage of a meteorite through the earth’s 
. atmosphere is to reduce very greatly its velocity, so that the speed of 
its fall when near the earth is comparable to that of an ordinary fall- 
ing body. Hence instead of striking the earth at a velocity of from 
to to 45 miles a second, which is that at which meteorites enter the 
atmosphere, their force of impact may be very small.) This is shown 
by the fact that several stones of the Hessle (298) fall, struck upon 
ice which was only a few inches thick and rebounded without either 
breaking the ice or being themselves shattered. 
By dissipating, therefore, the smaller stones before they reach the 
earth and by reducing both the size and velocity of those which do 
come to it, the atmosphere protects us from what would otherwise be 
a dangerous bombardment, and makes the chances of injury to life or 
property from the fall of these bodies exceedingly small. 
‘The forms of meteorites are very various and possess little regu- 
larity. Many are spheroidal (Pultusk, 290), some oblong (Babb’s 
Mill, cast, 383), some tetrahedral (Mocs, 330), some shell-like as if 
scaled from a spherical mass (Cation Diablo, 373) and many so irregu- 
lar as to be lacking any definite form. They areas a rule asindefi- 
nite as to size and shape as the fragments from any block of stone 
when shattered with a hammer and it is therefore probable that they 
have been formed by the breaking up of a larger mass, 
Such a disruption of a meteorite often takes place shortly before 
it reaches the earth, and as a result many individuals of a meteoric 
shower possess edges which are still rough and jagged and show little 
fusion of the surface (Winnebago Co,, 340), Perhaps the most remark- 
able instance of this is furnished by the stone of the Butsura (398) 
