A district in the Mandalay division of Upper Burma, lying along the Irrawaddy river between the Bhamo district on the N., the Shan States on the E., Mandalay district on the S. and Katha on the W. Including the Shan state of Mongmit, which is temporarily administered as part of the district, the total area is 5476 sq. m.; pop. (1901) 87,694. The district geographically forms part of the Shan plateau, and is to a great extent a mass of hills with a general N. and S. direction. It contains considerable numbers of Kachins (13,300) and Palaungs (16,400). The annual rainfall at Mogok averages 98 in. The administrative headquarters are at Mogok, which is also the centre of the ruby-mining industry. It stands in the centre of a valley 4000 ft. above sea-level, and is reached by a cart-road from Thabeikkyin, 61 m. distant, on the Irrawaddy. The Ruby Mines Company employs about 44 Europeans and Eurasians in its works, which are situated at the north end of the town. The company has constructed a dam across the Yeni stream and set up an electric installation of about 450 horse-power, which works pumps and the washing machinery. The mines were worked under Burmese rule, but were discontinued on account of the small profit. Now they seem to be established on a sound financial basis. The system adopted is to excavate large open pits, from which the rubyearth or byon is removed en masse and washed and crushed by machinery. Spinels and sapphires are found with the rubies. In 1904, the produce of rubies alone was 200,000 carats, valued at £80,000, most of which were sent to London for sale. In addition, some mining is carried on by natives, working under a licence which does not permit the use of machinery. The district contains 994 sq. m. of reserved forests.