‹‹‹ Vitr. 9.8.6 | Table of Contents | Vitr. 9.8.8 ›››
7If the addition or removal of the wedges should not be attended by a correspondent increase or decrease in the days, for the wedges are frequently imperfect, it is to be thus remedied. Let the hours from the analemma be placed on the column transversely, and let the lines of the months be also marked thereon. The column is to turn round, so that, in its continual revolution, the wand of the figure, as it rises, points to the hours, and, according to the respective months, makes the hours long or short.
7But if it proves that the shortening or lengthening of the day is not in agreement with the insertion and removal of the wedges, because the wedges may very often cause errors, the following arrangement will have to be made. Let the hours be marked off transversely on the column from the analemma, and let the lines of the months also be marked upon the column. Then let the column be made to revolve, in such a way that, as it turns continuously towards the figure and the rod with which the emerging figure points to the hours, it may make the hours short or long according to the respective months.