Ancient Horology is a fascinating but most difficult study, hampered by imperfect observation, the repetition of gross errors, and the free acceptance of mere tradition; so wide and deep is the confusion that careful students have now become cautious and sceptical even in accepting fairly admissible evidence. A contributory factor has been the undue separation of mechanical and artistic considerations, for mechanicians have attempted to form judgements based solely upon technical peculiarities, while artistic antiquaries have perhaps shunned the dark and oily wheels and levers hidden away in the dusty clock-chamber or tower. Certain types of clockwork cannot be dated unless there is ornament, but due attention to records, to mechanism, and to ornament, makes it at least possible to correct many erroneous traditions and false theories.