New spectroscopic observations are presented for a sample of thirty-one blue horizontal branch ( BHB ) star candidates that are sufficiently nearby to have reliable proper motions .
Comments are given on a further twenty-five stars that have previously been suggested as BHB star candidates but which were not included in our sample .
Moderately high-resolution spectra ( \lambda / \Delta \lambda \approx 15 000 ) of twenty five of our program stars were taken with the coudé feed spectrograph at Kitt Peak .
Twelve of the program stars were also observed with the CAT spectrograph at ESO .
Six of these program stars were observed from both hemispheres .
IUE low-resolution spectra are available for most of our candidates and were used , in addition to other methods , in the determination of their T _ { eff } and reddening .
A compilation of the visual photometry for these stars ( including new photometry obtained at Kitt Peak ) is also given .
Abundances were obtained from these spectra using models computed by Castelli with an updated version of the ATLAS9 code ( Kurucz 1993a ) .

All thirty one candidates are halo stars .
Of these , twenty eight are classified as BHB stars because :

( 1 ) they lie close to the ZAHB ( in a similar position to the BHB stars in globular clusters ) in the T _ { eff } versus \log g plot .
For all but one of these stars , far-UV data were available which were consistent with other data ( Strömgren photometry , energy distributions , H \gamma profiles ) for deriving T _ { eff } and \log g .

( 2 ) they have a distribution of v \sin i ( \leq 40 km s ^ { -1 } ) that is similar to that found for the BHB in globular clusters .
Peterson et al .
( 1995 ) and Cohen & McCarthy ( 1997 ) have shown that the BHB stars in the globular clusters M13 and M92 have a higher v \sin i ( \leq 40 km s ^ { -1 } ) than those in M3 and NGC 288 ( \leq 20 km s ^ { -1 } ) .
The mean deprojected rotational velocity ( \overline { v } ) was calculated for both the two globular clusters and the nearby BHB star samples .
A comparison of these suggests that both globular cluster v \sin i types are present in our nearby sample .
No obvious trend is seen between v \sin i and either ( B - V ) _ { 0 } or [ Fe/H ] .

( 3 ) they have - 0.99 \geq [ Fe/H ] \geq - 2.95 ( mean [ Fe/H ] - 1.67 ; dispersion 0.42 dex ) , which is similar to that found for field halo RR Lyrae and red HB stars .
These local halo field stars appear ( on average ) to be more metal-poor than the halo globular clusters .
The local sample of red giant stars given by Chiba & Yoshii ( 1998 ) contains a greater fraction of metal-poor stars than either our halo samples or the halo globular clusters .
The stars in our sample that have a T _ { eff } that exceeds about 8 500 K show the He i ( \lambda 4471 ) line with a strength that corresponds to the solar helium abundance .

( 4 ) they show a similar enhancement of the \alpha -elements ( < [ Mg/Fe ] > = +0.43 \pm 0.04 and also < [ Ti/Fe ] > = +0.44 \pm 0.02 ) to that found for other halo field stars of similar metallicity .