  During the 1996 HST/FOS monitoring campaign of the Seyfert 1 galaxy NGC 3516,
the UV continuum showed a factor of 5 variation; correspondingly the strongest
broad UV emission lines (e.g. Ly-alpha, CIV) displayed somewhat weaker, though
still significant variations (a factor of 2). In contrast, no variation was
detected in the strong broad MgII+UV FeII emission-line complex. While
historically the flux in the broad MgII emission line has varied (a factor of 2
within a few years), the profile shape has not been observed to change over the
past decade. In contrast, the high ionization lines (HILs) show both
emission-line flux and profile changes on relatively short timescales, which
appear to be correlated with changes in the continuum level. Significantly, on
1996, February 21, the profile shapes of the HILs (e.g. Ly-alpha, CIV) and low
ionization lines (LILs, e.g. MgII) were identical, at which time the continuum
level was at its highest. These results impose stringent constraints upon
viable kinematic models of the BLR in NGC 3516, some of which we discuss below.
