  We present three Far Ultraviolet Spectroscopic Explorer (FUSE) observations
of the Narrow-Line Seyfert 1 galaxy NGC4051. The most prominent features in the
far-ultraviolet (FUV) spectrum are the OVI emission and absorption lines and
the HI Lyman series absorption lines which are detected up to the Lyman edge.
We also identify weak emission from NIII, CIII, and HeII. The CIII line shows
absorption while none is detected in the NIII and HeII lines. In HI and CIII we
detect two main absorption systems at outflow velocities of -50+/-30 and
-240+/-40 km/s, as well as a possible third one at ~ -450 km/s. These systems
are consistent in velocity with the 10 absorption systems found previously in
CIV, NV, and SiIV, though the individual systems are blended together in the
FUV spectrum. We estimate column densities of the two main absorption systems
and find that the HI column density is lower for systems with larger outflow
velocity. We detect no flux or spectral variations of NGC4051 at FUV
wavelengths during three epochs spanning one year. This is consistent with the
optical light curve which shows no variations between the three epochs. It is
also consistent with the X-ray light curve which shows consistent flux levels
at the three epochs of the FUSE observations, although the X-ray light curve
shows strong variations on much shorter timescales.
