METEORITE COLLECTION—HANDBOOK AND CATALOGUE, 1s 
( Among characters common to all meteorites which distinguish 
them from bodies of terrestrial origin may be noted, fivs/, the varnish- 
like crust always found upon their surface. This is the result of heat- 
ing and Roe of the surface during passage of the mass through the 
atmosphere. ) / In the meteoric stones it is usually black and contrasts 
with the gray or brown of their interior (Winnebago Co., 340, Kny- 
ahinya, 287, Pultusk, 290). Not infrequently, however, it is of the 
same color as the interior (Kesen, 258, Washington Co., 345, and 
Phillips Co., 350). It isusually of a dull lustre (Pultusk, 291, Mocs, 
324), but occasonally shining (Stannern, 226, Knyahinya, 286). In 
many individuals it differs in appearance on different portions of the 
stone, being smooth and compact on one part and on another, rough 
and slag-like. 
Such appearances often indicate the position which the stone 
assumed during its fall, the portion bearing the smooth crust having 
been in advance (de Brustsette) while the other portion was at the 
rear (die Ruckenseite), (Winnebago Co., 340, Mocs, 331). On meteor- 
ites which are largely metallic, the crust appears as a brown (Grand 
Rapids, 116) or bluish (Estherville, 175) oxidation of the surface, con- 
trasting with the nickel-white color of the interior. It is never more 
than a millimeter in thickness (Forsyth, 241, New Concord, 273) and 
frequently exists only as a smoking of the surface (Winnebago, Co., 
340). 
Other evidences of surface fusion are seen in the rounded metal- 
lic beads which stand out over the exterior of most stony meteorites. } 
These are produced by metallic grains which offer a greater resist-| 
ance to heat than the non-metallic portions of the stone. Where the 
metallic grains are quite small, they give the surface a papillated 
appearance (Trenzano, 268, Bath, 351) but larger grains proeucs larger 
protuberances Rie chin ston Co., 347). 
Often there are visible on the crust of a meteorite (Stannern, 
226) lines of flow, which closely resemble, though on a much reduced 
scale, the features of a lava stream, and indicate that the surface of the 
meteorite was in a similar molten condition. 
The rounding of the solid angles and sharp edges observable in 
most meteoric individuals (Winnebago Co., 340), even metallic ones 
(Toluca, 12, 21), is likewise evidence of a fone: plastic condition of 
the exterior. ; 
{ A second common characteristic af meteorites is to be found in 
thd shallow pz¢s which indent their surface. These vary much in 
size and depth, but usually have an appearance much like that of an 
impression made by a thumb upon a piece of soft clay or putty. 
