We present high signal-to-noise integrated spectra of 24 star clusters in the Large Magellanic Cloud ( LMC ) , obtained using the FLAIR spectrograph at the UK Schmidt telescope .
The spectra have been placed onto the Lick/IDS system in order to test the calibration of Simple Stellar Population ( SSP ) models ( Maraston & Thomas 2000 ; Kurth , Fritz-von Alvensleben & Fricke 1999 ) .

We have compared the SSP-predicted metallicities of the clusters with those from the literature , predominantly taken from the Ca-Triplet spectroscopy of Olszewski et al .
( 1991 ) .
We find that there is good agreement between the metallicities in the range –2.10 \leq [ Fe/H ] \leq 0 .
However , the Mg _ { 2 } index ( and to a lesser degree Mg b ) systematically predict higher metallicities ( up to +0.5 dex higher ) than \langle Fe \rangle .
Among the possible explanations for this are that the LMC clusters possess [ \alpha /Fe ] > 0 .
Metallicities are presented for eleven LMC clusters which have no previous measurements .

We compare SSP ages for the clusters , derived from the H \beta , H \gamma and H \delta Lick/IDS indices , with the available literature data , and find good agreement for the vast majority .
This includes six old globular clusters in our sample , which have ages consistent with their HST CMD ages and/or integrated colours .
However , two globular clusters , NGC 1754 and NGC 2005 , identified as old ( \sim 15 Gyr ) on the basis of HST CMDs , have H \beta line-strengths which lead ages which are too young ( \sim 8 and \sim 6 Gyr respectively ) .
These findings are inconsistent with their CMD-derived values at the 3 \sigma level .
Comparison between the horizontal branch morphology and the Balmer line-strengths of these clusters suggests that the presence of blue horizontal branch stars has increased their Balmer indices by up to \sim 1.0 Å .

We conclude that the Lick/IDS indices , used in conjunction with contemporary SSP models , are able to reproduce the ages and metallicities of the LMC clusters reassuringly well .
The required extrapolations of the fitting-functions and stellar libraries in the models to younger ages and low metallicities do not lead to serious systematic errors .
However , due to the significant contribution of horizontal branch stars to Balmer indices , SSP model ages derived for metal-poor globular clusters are ambiguous without a priori knowledge of horizontal branch morphology .