The paper analyses three preserved reports, depicting Gerbert of Aurillac as a clockmaker. The Benedictine monk William of Malmesbury writes about clocks Gerbert made in Reims in The History of the English Kings and describes them as arte mechanica compositum. The Benedictine Arnold Wion mentions clocks from Ravenna, where Gerbert allegedly constructed a clepsydra, in The Tree of Life. In his Chronicle, Thietmar of Merseburg describes a horologium with an observation tube from Magdeburg. These three references are analysed from a (...) historical standpoint and especially Williams’s and Thietmar’s short reports are interpreted as possible references to timekeeping devices – the astrolabe and the nocturlabe. (shrink)