THE SARDIS METEORITE—HENDERSON AND COOKE 145 
Velocity and the angle of incidence are important factors in deter- 
mining the depth of penetration. An individual stone of the Hessle? 
fall weighing about 4 pounds was found on a frozen lake where it fell 
at a time when the ice was only a few inches thick. An object of this 
weight falling from only a mile high would exert 21,200 foot-pounds 
of energy, which surely would be sufficient to puncture the ice if this 
force were applied in a direction normal to the surface. 
Since the individual stone failed to break the ice, the meteorite 
must have either approached the ice with a high angle of incidence 
or for some reason had its velocity greatly reduced. Recorded state- 
ments of eyewitnesses indicate that the Hessle meteorite had a remark- 
ably small downward velocity. 
The Allegan, Mich., meteorite weighing 70 pounds penetrated a 
sandy soil only about 18 inches, but this stony fall, when recovered, 
was considerably shattered. The 660-pound Knyahinya stony mete- 
orite struck the ground at an estimated angle of about 25° from the 
vertical and penetrated to a depth of 11 feet. The Hraschina, a 
71-pound iron, was reported to have penetrated 18 feet; the 820-pound 
Paragould, Ark., stone, a witnessed fall, penetrated the clay soil to 
8 feet. The Hugoton, Kans., meteorite, a 749-pound stone, was recov- 
ered in a cornfield where it, too, was discovered by fouling the plow- 
point. The base of the Hugoton was only 3 feet below the present 
surface of the field, but this stone may be a very old fall, and much 
of its covering had been eroded away. 
Nininger ? has summarized some information on the average depths 
of individuals according to their weight: 
Number of individuals Wietenr oF speci- | Depth of 
penetration 
Pounds Inches 
ge ge er ape RE PE ae Oe Sp Se 50—100 32 
REESE LEU RE |g IS AE Sn ae EE eS 100—200 43 
rT Es pos ies be Me fa a, ea at RS ke a 200-400 48 
In the Odessa crater of Ector County, Tex., which has been under 
investigation for some time, recent work indicates that perhaps a 
large mass of this fall has been located. “Two test holes, 10 feet apart, 
encountered at a depth of 164 feet, a mass that was essentially un- 
affected by pounding of the 1,500-pound drilling bit. This is believed 
to be a meteorite.” 3 
1Flight, Walter, History of meteorites, p. 2, 1887. London. 
?Nininger, H. H., Depth of meteorites and gradation of the Great Plains. Journ. 
Geol., vol. 44, No. 1, p. 66, 1936. 
3 Sellards, E. H., Private communication. 
