South African Class 15E 4-8-2 on 26 July 1992, while the following pictures illustrate some differences in appearance over the years. South African Class 15E 4-8-2 The South African Railways Class 15E 4-8-2 of 1935 was a steam locomotive. Between 1935 and 1937, the South African Railways placed forty-four Class 15E steam locomotives with a 4-8-2 Mountain type wheel arrangement in service. The Class 15E 4-8-2 Mountain type mixed traffic steam locomotive was a refinement of the Classes 15C and 15CA. It was designed by A.G. Watson, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1929 to 1936, and incorporated many of
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