In the case of porcelain, where different materials and higher firing-temperatures are used, the physical, chemical and mineralogical properties of the constituents in the body are greatly altered. In all cases, the object of firing is to permanently harden the wares and the firing regime must be appropriate to the materials used to make them.
Firing pottery can be done using a variety of methods, with a kiln being the usual firing method. Both the dating all hours temperature and the duration of firing influences the final characteristics of the ceramic. Thus, the maximum temperature within a kiln is often held constant for a period of time to soak the wares to produce the maturity required in the body of the wares.
The atmosphere within a kiln during firing can affect the appearance of the finished wares. An oxidising atmosphere, produced by allowing air to enter the kiln, can cause the oxidation of clays and glazes.
Prior to the British conquest of Palestine, the Ottomans had recognized the leading rabbis of the Old Yishuv as the official leaders of the small Jewish community that for many centuries consisted mostly of the devoutly Orthodox Jews from Eastern Europe as well as those from the Levant who had made aliyah to the Holy Land, primarily for religious reasons.
The European immigrants had unified themselves in an organization initially known as the Vaad Ha'irwhich later changed its name to Edah HaChareidis. Thus the centrality of an Orthodox dominated Chief Rabbinate became part of the new state of Israel as well when it was established in Through a complex system of ""advice and consent"" from a variety of senior rabbis and influential politicians, each Israeli city and town also gets to elect its own local Orthodox Chief Rabbi who is looked up to by substantial regional and even national religious and even non-religious Israeli Jews.
Through a national network of Batei Din ""religious courts""each headed only by approved Orthodox Av Beit Din judges, as well as a network of ""Religious Councils"" that are part of each municipality, the Israeli Chief Rabbinate retains exclusive control and has the final say in the state about virtually all matters pertaining to conversion to Judaismthe Kosher certification of foodsthe status of Jewish marriages and divorcesand monitoring and acting when called upon to supervise the observance of some laws relating to Shabbat observance, Passover particularly when issues concerning the sale or ownership of Chametz come upthe observance of the Sabbatical year and the Jubilee year in the agricultural sphere.