  We describe a simple construction of Kingman's coalescent in terms of a
Brownian excursion. This construction is closely related to, and sheds some new
light on, earlier work by Aldous and Warren. Our approach also yields some new
results: for instance, we obtain the full multifractal spectrum of Kingman's
coalescent. This complements earlier work on Beta-coalescents by the authors
and Schweinsberg. Surprisingly, the thick part of the spectrum is not obtained
by taking the limit as $\alpha \to 2$ in the result for Beta-coalescents
mentioned above. Other analogies and differences between the case of
Beta-coalescents and Kingman's coalescent are discussed.
