  The results from deep long-slit spectroscopy of nine edge-on spiral galaxies
with known extraplanar line emission are reported. Emission from Halpha, [N II]
lambda 6548, 6583, and [S II] lambda 6716, 6731 is detected out to heights of a
few kpc in all of these galaxies. Several other fainter diagnostic lines such
as [O I] lambda 6300, [O III] lambda 4959, 5007, and He I lambda 5876 are also
detected over a smaller scale. The relative strengths, centroids and widths of
the various emission lines provide constraints on the electron density,
temperature, reddening, source(s) of ionization, and kinematics of the
extraplanar gas. In all but one galaxy, photoionization by massive OB stars
alone has difficulties explaining all of the line ratios in the extraplanar
gas. Hybrid models that combine photoionization by OB stars and another source
of ionization such as photoionization by turbulent mixing layers or shocks
provide a better fit to the data. The (upper limits on the) velocity gradients
measured in these galaxies are consistent with the predictions of the galactic
fountain model to within the accuracy of the measurements.
