Cable cars rapidly spread to other cities, although the major attraction for most was the ability to displace horsecar (or mule-drawn) systems rather than the ability to climb hills. Many people at the time viewed horse-drawn transit as unnecessarily cruel, and the fact that a typical horse could work only four or five hours per day necessitated the maintenance of large stables of draft animals that had to be fed, housed, groomed, medicated and rested. Thus, for a period, economics worked in favour of cable cars even in relatively flat cities.