  In this note we study metastability phenomena for a class of long-range Ising
models in one-dimension. We prove that, under suitable general conditions, the
configuration -1 is the only metastable state and we estimate the mean exit
time. Moreover, we illustrate the theory with two examples (exponentially and
polynomially decaying interaction) and we show that the critical droplet can be
macroscopic or mesoscopic, according to the value of the external magnetic
field.
