English Dominican mysticism in the late medieval period differed from European strands of it in that, whereas European Dominican mysticism tended to concentrate on ecstatic experiences of union with the divine, English Dominican mysticism's ultimate focus was on a crucial dynamic in one's personal relationship with God. This was an essential moral imitation of the Savior as an ideal for religious change, and as the means for reformation of humanity's nature as an image of divinity. This type of mysticism carried with it four elements. First, spiritually it emulated the moral essence of Christ's life. Second, there was a connection linking moral emulation of Christ's life and humanity's disposition as images of the divine. Third, English Dominican mysticism focused on an embodied spirituality with a structured love of fellow men at its center. Finally, the supreme aspiration of this mysticism was either an ethical or an actual union with God.
What did European mysticism concentrate on that English mysticism didn't?
ecstatic experiences of union with the divine

Commercial solar water heaters began appearing in the United States in the 1890s. These systems saw increasing use until the 1920s but were gradually replaced by cheaper and more reliable heating fuels. As with photovoltaics, solar water heating attracted renewed attention as a result of the oil crises in the 1970s but interest subsided in the 1980s due to falling petroleum prices. Development in the solar water heating sector progressed steadily throughout the 1990s and growth rates have averaged 20% per year since 1999. Although generally underestimated, solar water heating and cooling is by far the most widely deployed solar technology with an estimated capacity of 154 GW as of 2007.
Why did interest in solar water heating decrease in the 1980s?
falling petroleum prices

In the medieval period the wall circuit was expanded. Via Vittorio Emanuele continued to be the main road east-west through the walled city. West gate was still Porta Nuova, the circuit continued to Corso Alberti, to Piazza Vittorio Emanuele Orlando where it turned east along Via Volturno to Piazza Verdi and along the line of Via Cavour. At this north-east corner there was a defence, Castello a Mare, to protect the port at La Cala. A huge chain was used to block La Cala with the other end at S Maria della Catena (St Mary of the Chain). The sea-side wall was along the western side of Foro Italico Umberto. The wall turns west along the northern side of Via Abramo Lincoln, continues along Corso Tukory. The wall turns north approximately on Via Benedetto, to Palazzo dei Normanni and back to Porta Nuova. Source: Palermo - City Guide by Adriana Chirco, 1998, Dario Flaccovio Editore.
During which historical period was the wall circuit expanded?
medieval