A major advance in obtaining reliable temperatures
of the optically thick, stratified W-R stars has been through
the Standard Model, since standard methods are insensistive for
hot stars (e.g. Hummer et al. 1988). Stellar temperatures for extended
atmospheres are related to the inner boundary of the model atmosphere
(generally around Rosseland optical depth 
20), which
often deviates significantly from the effective temperature, related to
=2/3 (see Hamann 1994). For WN stars, stellar temperatures
lie in the approximate range 30--100kK, while effective temperatures
are typically 25--40kK (Hamann et al. 1995).
HD104994 (WN3pec, Crowther et al. 1995d) is amongst the hottest W-R stars
known, while the LMC star R84 (WN9, Crowther et al. 1995a) is one of
the coolest (see Table 1), supporting the anticipated relation
between temperature and spectral type. Although most WC
stars have still to be analysed in detail,
they show a similar range (Koesterke & Hamann 1995).
Luminosities of W-R stars span a wide range 
=10
, with
the most luminous stars exclusively WNL stars, and the least luminous generally
WNE and WCE. The presence of low luminosity WNE stars containing surface
hydrogen is difficult to reconcile with standard evolutionary theory,
without resorting to unrealistic mass-loss prior to the W-R phase (Crowther
et al. 1995d).
Table 1: Comparison of properties of early--type, emission line stars.
The parameters for AG Car relate to its WN11 visual minimum phase.
Abundances are by mass