Smithsonian Report. 1931. — Jeans 



Plate 1 



The Veil Nebula iN. G. c. 6992) in the Constellation of Cygnus. Within 

 THE Confines of the Milky Way 



NebuliiP, plasslficil acr<ircllim (o their rliiuuctprlstio.s, comprise dark nebulae, illlTii.se IuiiiIikiu.s nebulae, 

 planetary nebulae, elllplical nebulae, ;iiiil .spiral nebulae. The first three classes ;ire fduiiil only in or 

 near the region of the .Milky Way. .Members of the last two classes lie dutside the tlalaciic System 

 (system of the Milky Way) and are called "e-xlra-galactie nebulae," "island universes," "star-cities." 

 The Veil Nebula belongs to the "diffuse" type and consists of dust and luminous gas. 



