Boart Longyear samples for the proposed Golden Gate Bridge in San Francisco. In spite of the financial crisis, the 1930s saw improvements in diamond drilling technology, including the use of industrial-quality diamonds mined in Africa that were called “boarts.” In 1936, South Africa’s Anglo American Corporation formed Boart Products South Africa (Pty) Limited, which was later named Boart International. The new company developed the first mechanically-set diamond core bits, which were less expensive than the hand-set core bits that used more expensive Brazilian diamonds (carbonados). Longyear’s business gradually improved in the 1940s in response to expanding worldwide mineral exploration. In 1949, the
Pierre Edmond Teisserenc de Bort which had been made by him during his 1876 ministry. In 1879 he was sent as ambassador to Vienna, whence he was next year recalled on the score of health. Two years later he re-entered the Senate, where he did good service to the cause of "Republican Defence" during the Boulangist agitation. His works consist of discussions of railway policy from the technical and economic side. Pierre Edmond Teisserenc de Bort Pierre Edmond Teisserenc de Bort (17 September 1814 at Châteauroux – 29 July 1892 in Paris), was a French writer and politician. He entered the civil service after the