Zanzibar
2 of the 7 encyclopedias on this shelf carry an entry for Zanzibar. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a British protectorate in east Africa, which formerly comprised the whole coast between Magdishu and Cape (Magadoxo), about lat. 2° N., and Delgado, lat. 10° 42′ S., with the four islands of Zanzibar, Pemba, Lamu, and Mafia. The continental part of the protectorate has become part of British East Africa and German East Africa; while the island and town of Zanzibar, and the island of Pemba, are entirely under British protection. The island (area 600 square miles) is very fertile and well cultivated, being especially suited for the cultivation of cloves, sugar, coffee, cocoa, and various spices, of which there is a considerable export. The population (200,000) is extremely heterogeneous, including Europeans, Arabs, half-caste Portuguese from the Malabar coast of India, and the Suahilis from the mainland. In 1899 Germany removed her rights of extra-territoriality in Zanzibar from such time as the similar rights possessed there by Great Britain should be abolished. The imports in 1899 had a value of $7,983,030, and the exports, $7,567,035. ZANZIBAR, Cyc comedietta; "Without Prejudice" the chief town (100,000 inhabitants), on Ghetto" the W. side of the island, is the center (1898); "They That Walk in Darkness" of trade for the E. seaboard of Africa and of missionary and exploring work for the interior. At the instance of the British Government the slave trade has been abolished and slavery was nominally abolished in 1897.
Aiton's Encyclopedia (1910)
a British protectorate. It consists chiefly of the islands of Zanzibar and Pemba lying in the Indian Ocean off the coast of East Africa . The protectorate has a total area of 1,020 square miles and an estimated population of 226,000. The Arabs, about 10,000 in number, are the dominant element. The port of Zanzibar has a population of about 56,000. Most of the natives are Mohammedans. There are Christian missions, both Protestant and Catholic. The chief product of the island is cloves. In 1907 16,263,100 pounds, over 8,000 tons, of cloves were exported. Other exports are copra and ivory. The imports and exports amount to about $5,000,000 each yearly, but a large part of this business consists of merchandise handled for the mainland.