John Couch Adams	Walter S. Adams	Walter Baade	Edward Emerson Barnard
FIG. l-01	FIG. l-02	FIG. l-03	FIG. l-04
by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific
Ira S. Bowen	Tycho Brahe	William Wallace Campbell	Annie Jump Cannon
FIG. l-05	FIG. l-06	FIG. l-07	FIG. l-08
by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific
Alvar Clark	Nicholas Copernicus	Heber D. Curtis	Willem DeSitter
FIG. l-09	FIG. l-10	FIG. l-11	FIG. l-12
by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific
Henry Draper	Arthur Stanley Eddington	Albert Einstein	Galileo Galilei
FIG. l-13	FIG. l-14	FIG. l-15	FIG. l-16
by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific
George Ellery Hale	Asaph Hall	John F. W. Herschel	William Herschel
FIG. l-17	FIG. l-18	FIG. l-19	FIG. l-20
by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific
Ejnar Hertzsprung	Edwin P. Hubble	Sir William Huggins	Milton Humason
FIG. l-21	FIG. l-22	FIG. l-23	FIG. l-24
by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific	by: The Astronomical society of the Pacific