Experimental results and a detailed analysis are presented of the tran
sverse energy and charged particle azimuthal distributions measured by
the E877 Collaboration for different centralities of Au+Au collisions
at a beam momentum of 10.8A GeV/c. The anisotropy of these distributi
ons is studied with respect to the reaction plane reconstructed on an
event-by-event basis using the transverse energy distribution measured
by calorimeters. Results are corrected for the reaction plane resolut
ion. For semicentral events we observe directed flow signals of up to
10%. We observe a stronger anisotropy for slow charged particles. For
both the charged particle and transverse energy distributions we obser
ve a small but nonzero elliptic anisotropy with the major axis pointin
g into the reaction plane. Combining the information on transverse ene
rgy and charged particle flow we obtain information on the flow of nuc
leons and pions. The data are compared to event generators and the nee
d to introduce a mean field or nucleon-nucleon potential is discussed.