South African Class 19A 4-8-2 South African Class 19A 4-8-2 The South African Railways Class 19A 4-8-2 of 1929 was a steam locomotive. In 1929, the South African Railways placed 36 Class 19A steam locomotives with a 4-8-2 Mountain type wheel arrangement in service. Five of them were later reboilered and reclassified to Class 19AR. The Class 19A 4-8-2 Mountain type steam locomotive was a later modified version of the successful Class 19 which had been introduced a year earlier. Thirty-six Class 19A engines were delivered by Swiss Locomotive and Machine Works (SLM) of Winterthur in 1929, numbered in the range from 675 to 710.
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