  Observations of the interstellar medium in the vicinity of the Orion OB1
association show a cavity filled with hot ionized gas, surrounded by an
expanding shell of neutral hydrogen (the Orion-Eridanus Bubble). In this paper
we examine this cavity and the surrounding bubble with the aid of data from the
Leiden/Dwingeloo HI survey. We present neutral-hydrogen maps for the
Orion-Eridanus region which allow identification of the HI filaments and arcs
delineating the Bubble and derivation of its expansion velocity. The HI data
are compared to X-ray, CO and IRAS 100 micron data. Using models of wind blown
bubbles that take the density stratification of the Galactic HI layer into
account we show that the stellar winds and supernovae from stars in Orion OB1
can account for the size as well as the expansion velocity of the HI shell.
However, density inhomogeneities in the ambient interstellar medium cause
significant discrepancies between our model and the observed shell.
