Summary: Recently P. G. Harrison [ibid. 33, 464-468 (1985; Zbl 0564.60087)] derived a closed form solution for the normalizing constant of a closed network of single server queues. In the present paper, we describe an alternative method of obtaining Harrison’s result. The new method can usefully be applied to other closed networks of queues, particularly those in which irregular constraints bound the state space. Examples of the method are provided, and several new results are obtained.