  We observed 42 molecular condensations within previously identified
bright-rimmed clouds in the ammonia rotational inversion lines NH3 (1,1),
(2,2), (3,3) and (4,4) using the Green Bank Telescope in Green Bank, West
Virginia. Using the relative peaks of the ammonia lines and their hyperfine
satellites we have determined important parameters of these clouds, including
rotational temperatures and column densities.
  These observations confirm the presence of dense gas towards IRAS point
sources detected at submillimetre wavelengths. Derived physical properties
allow us to refine the sample of bright-rimmed clouds into those likely to be
sites of star formation, triggered via the process of radiatively-driven
implosion. An investigation of the physical properties of our sources show that
triggered sources are host to greater turbulent velocity dispersions, likely
indicative of shock motions within the cloud material. These may be attributed
to the passage of triggered shocks or simply the association of outflow
activity with the sources.
  In all, we have refined the Sugitani et al. (1991) catalogue to 15 clouds
which are clearly star-forming and influenced by external
photoionisation-induced shocks. These sources may be said, with high
confidence, to represent the best examples of triggering within bright-rimmed
clouds.
