Amor Fenn, Design and Tradition
“ In a balustrading an unequal number of balusters should always be used, and not less than five in one group exclusive of the half balusters which are attached to the flanking or dividing dies. Seven and nine form very satisfactory groups, but if more than nine are necessary for the space to be filled, intermediate dies must be interposed, and these may vary from two-thirds to three-quarters the width of the principal dies.In some cases, when a large number of balusters are to be grouped, the dies are flanked by half dies, which are less in projection than the dies themselves. ”
