ASTRONOMY : H. SHAPLEY 
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this viewpoint the Milky Way is mainly a phenomenon of depth; its extent, 
as seen from the sun, is something like three times as great in the direction of 
the center as in the opposite direction toward Auriga and Taurus. The tes- 
timony of the star frequencies in the Milky Way clouds does not disagree with 
the supposition of a remarkably eccentric position of the solar system. 
Slipher's radial velocity observations of the brighter globular clusters 2 indi- 
cate that seven out of eight of those with high galactic latitudes are approach- 
ing the sun (and probably the equatorial segment) with such high velocities 
that, unless greatly retarded, they will have entered the dense stellar regions 
within an interval of time which appears to be short as compared with the 
probable history of a stellar system. The absence of such clusters from the 
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FIG. 3. PROJECTION OF THE POSITIONS OF GLOBULAR CLUSTERS ON A PLANE 
PERPENDICULAR TO THE GALAXY 
Illustrating (1) the absence of clusters from the mid-galactic region, (2) their symmetrical 
arrangement with respect to the Galaxy, (3) the eccentric position of the sun (the cross) 
with respect to the center of the system of clusters. The ordinates are distances from the 
galactic plane, R sin /?; the abscissae are projected distances in the direction of the center, 
R cos 0 cos (X — 325°). The unit of distance is 100 parsecs (326 light-years); each 
small square is 10,000 parsecs on a side. On this scale the actual diameter of each cluster 
is about one-fifth the diameter of the circles and dots. The cluster N.G.C. 4147 is outside 
the boundary of the diagram, as indicated by the arrow. 
Galaxy thus becomes the more remarkable. The globular systems nearest the 
galactic plane are in general the least condensed. This result and the distribu- 
tion of stars in certain open clusters suggest the possibility that upon approach- 
ing the galactic regions globular clusters may be disrupted and transformed 
into open galactic groups. 
The galactic center as derived from the clusters is nearly at right angles to 
the direction of center obtained by Walkey and Charlier from statistical inves- 
