The principal ports are St. Petersburg, Cronstadt, Narva, Riga, Libau, Pernau and Vindau (on the Baltic); Hango (on the Gulf of Bothnia); Revel, Helsingfoers and Wiborg (on the Gulf of Finland); Archangel and Ekaterinsk (Arctic and White Seas); Odessa, Nicolaieff, Sebastopol, Nova-Rossiisk, Berdiansk and Batoum, Taganrog, Marinpol, Rostov and Kertch (on the Black Sea and Sea of Azov); Astrakhan, Derbent and Baku (on the Caspian Sea); Nicolaieffsk, Vladivostok and Petrapaulovsk in Kamtchatka; and Port Arthur and Dalni or Ta-lien-wan (Gulf of Pechili), have been occupied since the Russo-Chinese Treaty of 1898. The established religion is the Russo-Greek, or Graeco-Russian, known officially as the Orthodox Catholic Faith. It maintains the relations of a sister church with the four patriarchates of Constantinople, Antioch, Jerusalem and Alexandria. The Emperor is the head of the church. The Russian Empire is divided into 64 bishoprics, under 3 metropolitans, 14 archbishops and 48 bishops; in 1898, there were 66,146 churches (718 of which were cathedrals), and 785 monasteries. With the exception of the Jewish, all religions are allowed to be professed. There are more than 12,000,000 dissenters scattered throughout the Empire. The numbers are: Orthodox Greek, 87,384,480; Dissenters, 2,173,738; Roman Catholic, 11,420,927; Protestants, 3,743,209; other Christians, 1,221,511; Mohammedans, 13,889,421; Jews, 5,189,401; and other religions, 645,503. In 1903, the Holy Synod received 28,388,049 roubles from the Imperial budget, besides other revenue and gifts. The Empire is divided into 15 educational districts: St. Petersburg, Moscow, Kasan, Orenburg, Kharkoff, Odessa, Kief, Vilna, Warsaw, Riga, Caucasus, Turkestan, West Siberia, East Siberia and Amur. In some of the primary village schools, there are school-gardens, while bee-keeping and silk-worm culture, as well as trades and handiwork, are taught. In 1900, the Ministers contributed 51,062,842 roubles for schools and universities. The universities are in Moscow (4,344 students in 1902); St. Petersburg (3,708); Kief (2,316); Kharkov (1,340); Dorpat (1,791); Warsaw (1,312); Kasan (823); Odessa (1,116); and Tomsk (549). Helsingfors, Finland, had 1,211 students in 1900-1. Since 1874 military service has been obligatory for all men from the age of 21. The period of service in European Russia is five years in the active army (reduced by furloughs to four) 13 in the Zapas those who have passed through active service and five years in the Opolchenie, or reserve; in Asiatic Russia, seven years in the active army and six in the Zapas; and in Caucasia, three years in the active army and 15 in the Zapas. The Opolchenie is a reserve force of drilled conscripts.