South African Class 15A 4-8-2 of these locomotives had completed three million miles of heavy-duty mainline work. The table lists the Class 15A engine numbers, builders, years built, works numbers and eventual classifications. The main picture shows reboilered 1914-built Class 15A no. 1788 at Graaff Reinet on 4 April 1978. Differences between the various locomotive models are illustrated in the pictures below. South African Class 15A 4-8-2 The South African Railways Class 15A 4-8-2 of 1914 was a steam locomotive. Between 1914 and 1925, the South African Railways placed 119 Class 15A steam locomotives with a 4-8-2 Mountain type wheel arrangement in service, delivered in
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