South African Class 23 4-8-2 South African Class 23 4-8-2 The South African Railways Class 23 4-8-2 of 1938 was a steam locomotive. In 1938 and 1939, the South African Railways placed 136 Class 23 steam locomotives in service. The Class 23 was the last and the largest 4-8-2 Mountain type locomotive to be designed by the South African Railways. The Class 23 4-8-2 Mountain type steam locomotive was designed by W.A.J. Day, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1936 to 1939. It was intended as a general utility locomotive, capable of operating on rail, and was built in two
1/2 + 1/4 + 1/8 + 1/16 + ⋯ 1/2 + 1/4 + 1/8 + 1/16 + ⋯ In mathematics, the infinite series is an elementary example of a geometric series that converges absolutely. There are many different expressions that can be shown to be equivalent to the problem, such as the form: 2 + 2 + 2 + ... The sum of this series can be denoted in summation notation as: As with any infinite series, the infinite sum is defined to mean the limit of the sum of the first terms as approaches infinity. Multiplying by 2 reveals a useful relationship: Subtracting from both sides, As approaches