  We report new branching fraction measurements for 199 UV and optical
transitions of Hf II. These transitions range in wavelength (wavenumber) from
2068- 6584 A (48322-15183 cm-1) and originate in 17 odd-parity upper levels
ranging in energy from 38578-53227 cm-1. The branching fractions are combined
with radiative lifetimes reported in an earlier study to produce a set of
transition probabilities and log(gf) values with accuracy ranging from 5-25%.
Comparison is made to transition probabilities from the literature where such
data exist. We use these new transition probabilities to derive improved Hf
abundances in two metal-poor stars. HD 196944 is enhanced in s-process
elements, and we derive log epsilon (Hf) = -0.72 +/- 0.03 (sigma = 0.09) from
12 Hf II lines. HD 222925 is enhanced in r-process elements, and we derive log
epsilon (Hf) = 0.32 +/- 0.03 (sigma = 0.11) from 20 Hf II lines. These
measurements greatly expand the number of potentially useful Hf II lines for
analysis in UV and optical spectra.
