We present the results of analysis of “ snapshot ” spectra of 253 metal-poor halo stars -3.8 \leq \mathrm { [ Fe / H ] } \leq - 1.5 obtained in the HERES survey .
The snapshot spectra have been obtained with VLT/UVES and have typically S / N \sim 54 per pixel ( ranging from 17 to 308 ) , R \sim 20000 , \lambda = 3760–4980 Å .
This sample represents the major part of the complete HERES sample of 373 stars ; however , the CH strong content of the sample is not dealt with here .

The spectra are analysed using an automated line profile analysis method based on the Spectroscopy Made Easy ( SME ) codes of Valenti & Piskunov .
Elemental abundances of moderate precision ( absolute rms errors of order 0.25 dex , relative rms errors of order 0.15 dex ) have been obtained for 22 elements , C , Mg , Al , Ca , Sc , Ti , V , Cr , Mn , Fe , Co , Ni , Zn , Sr , Y , Zr , Ba , La , Ce , Nd , Sm , and Eu , where detectable .
Of these elements , 14 are usually detectable at the 3 \sigma confidence level for our typical spectra .
The remainder can be detected in the least metal-poor stars of the sample , spectra with higher than average S / N , or when the abundance is enhanced .

Among the sample of 253 stars , disregarding four previously known comparison stars , we find 8 r-II stars and 35 r-I stars .
The r-II stars , including the two previously known examples CS 22892-052 and CS 31082-001 , are centred on a metallicity of \mathrm { [ Fe / H ] } = -2.81 , with a very small scatter , on the order of 0.16 dex .
The r-I stars are found across practically the entire metallicity range of our sample .
We also find three stars with strong enhancements of Eu which are s-process rich .
A significant number of new very metal-poor stars are confirmed : 49 stars with \mathrm { [ Fe / H ] } < -3 and 181 stars with -3 < \mathrm { [ Fe / H ] } < -2 .
We find one star with \mathrm { [ Fe / H ] } < -3.5 .

We find the scatter in the abundance ratios of Mg , Ca , Sc , Ti , Cr , Fe , Co , and Ni , with respect to Fe and Mg , to be similar to the estimated relative errors and thus the cosmic scatter to be small , perhaps even non-existent .
The elements C , Sr , Y , Ba and Eu , and perhaps Zr , show scatter at \mathrm { [ Fe / H ] } \la - 2.5 significantly larger than can be explained from the errors in the analysis , implying scatter which is cosmic in origin .
Significant scatter is observed in abundance ratios between light and heavy neutron-capture elements at low metallicity and low levels of r-process enrichment .