In the society and culture the Master was developing, spiritual energies expressed themselves in the practical affairs of day-to-day life. The emphasis in the teachings on education provided the impulse for the establishment of Bahá’í schools—including the Tarbíyat school for girls,(11) which gained national renown—in the capital, as well as in provincial centres. With the assistance of American and European Bahá’í helpers, clinics and other medical facilities followed. As early as 1925, communities in a number of cities had instituted classes in Esperanto, in response to their awareness of the Bahá’í teaching that some form of auxiliary international language must be adopted. A network of couriers, reaching across the land, provided the struggling Bahá’í community with the rudiments of the postal service that the rest of the country so conspicuously lacked. The changes under way touched the homeliest circumstances of day-to-day life. In obedience to the laws of the Kitáb-i-Aqdas, for example, Persian Bahá’ís abandoned the use of the filthy public baths, prolific in their spread of infection and disease, and began to rely on showers that used fresh water. All of these advances, whether social, organizational or practical, owed their driving force to the moral transformation taking place among the believers, a transformation that was steadily distinguishing Bahá’ís—even in the eyes of those hostile to the Faith—as candidates for positions of trust. That such far-reaching changes could so quickly set one segment of the Persian population apart from the largely antagonistic majority around it was a demonstration of the powers released by Bahá’u’lláh’s Covenant with His followers and by ‘Abdu’l-Bahá’s assumption of the leadership this Covenant invested uniquely in Him.