  The size distribution of geometrical spin clusters is exactly found for the
one dimensional Ising model of finite extent. For the values of lattice
constant $\beta$ above some "critical value" $\beta_c$ the found size
distribution demonstrates the non-monotonic behavior with the peak
corresponding to the size of largest available cluster. In other words, at high
values of lattice constant there are two ways to fill the lattice: either to
form a single largest cluster or to create many clusters of small sizes. This
feature closely resembles the well-know bimodal size distribution of clusters
which is usually interpreted as a robust signal of the first order liquid-gas
phase transition in finite systems. It is remarkable that the bimodal size
distribution of spin clusters appears in the one dimensional Ising model of
finite size, i.e. in the model which in thermodynamic limit has no phase
transition at all.
