July, 1914. New Meteorites — Farrington. 5 



nearly vertical or inclined inwards from front to back. On the remain- 

 ing side the edge narrows down to close contact between the front and 

 rear sides. The greatest and least diameters of the front surface of 

 the shield are 32 inches (78 cm.) and 26 inches (68 cm.). The mass is 

 well oriented, there being notable differences in the markings and appear- 

 ance of the front or apical side as compared with those of the rear or 

 basal side. The boss of the shield is not centrally located as regards the 

 outline of the shield, but is much at one side. However, it appeared 

 from the behavior of the mass in handling it for installation that this 

 boss or apex is close' to the center of gravity of the mass. The boss does 

 not present a broad, smooth surface, as is frequent with meteorites of 

 this form, but is roughened and furrowed. The furrows extend radially 

 from the boss over a considerable part of the front surface of the mass. 

 They doubtless mark the course of air currents which diverged from the 

 boss as the meteorite passed through the earth's atmosphere. The 

 tendency of a meteorite in passing through the atmosphere to acquire 

 a conical form through the greater erosion by atmospheric currents of 

 the periphery of its front is illustrated in the accompanying diagram, 

 Fig. 1 . The front portion of the meteorite may be considered as subjected 

 to both vertical and lateral forces of erosion. The resultant force 

 will therefore be represented by a diagonal which is greater than 

 either and moves in a direction tending to produce a conical form. Other 

 portions of the meteorite are acted upon by only one of these forces and 

 hence are less affected. If the meteorite is relatively broad in proportion 

 to its thickness, the lateral force becomes stronger and the broad 

 surface tends to be maintained. 



Passing from a consideration of the general form of the Davis Moun- 

 tains meteorite to its superficial markings, its front surface will be found 

 to be irregularly indented by depressions covering several square inches 

 each. These are secondarily modified by smaller depressions which 

 resemble the more usual meteorite pittings except that they are irregular 

 and ill-defined. Interspersed with these depressions are long ridges, 

 the longest of which extends in an irregular course from the boss to the 

 most distant point of the meteorite. The surface of this ridge is marked 

 by a brighter luster and lighter color than the rest of the mass. At the 

 end of the meteorite farthest from the boss this ridge passes over the 

 thick, perpendicular edge of the meteorite in a sinuous course. This is 

 at the apex of the triangle. The ridge is also strikingly marked by a 

 continuous series of striae running in a direction nearly normal to its 

 course. These striae vary in length and depth, but none of them is over 

 a foot in length or more than a millimeter deep. While in a general way 

 they all take the same course, there are some deviations and some of the 



