  Experimental results for the susceptibility, specific heat, 4f occupation
number, Hall effect and magnetoresistance for single crystals of YbAl$_{3}$
show that, in addition to the Kondo energy scale $k_{B}T_{K}$ $% \sim $ 670K,
there is a low temperature scale $T_{coh}<50$K for the onset of coherence.
Furthermore the crossover from the low temperature Fermi liquid regime to the
high temperature local moment regime is slower than predicted by the Anderson
impurity model. These effects may reflect the behavior of the Anderson Lattice
in the limit of low conduction electron density.
