E quibus quae maxime utilia et necessaria iudicavi selegi, et in priore volumine de horologiis, in hoc de expressionibus aquae dicendum putavi.
Of these I have chosen those which I have judged most useful and serviceable. In the last book I spoke about clocks; in this we have had to deal with water-pumps.
final_alignments\Vitruvius_Architecture_Book_10.json