“In a museum I saw a very old hourglass”. Can you tell time by looking at the hourglass? Probably not as easily as with “orologio”. Is “clessidra” the word for hourglass and “orologio” for “watch” and “clock”?
I think a mistake might have been made here by the person providing and linking the Italian translation to the English sentence on Tatoeba, because all the other versions of the Esperanto sentence do seem to correspond to “hourglass” instead of “watch”.