In 1877 the maximum annual output for the mines was attained, being $3 6, 3 01, 537.
The output for the year is less than 4000 tons.
Since high average speed on a line with frequent stops depends largely on rapidity of acceleration, the tendency in modern equipment is to secure as great an output of power as possible during the accelerating period, with corresponding increase in weight available for adhesion.
The value of the output in 1905 was £226,110.
A successful well in Marion county, near Mannington, far from the region of the earlier wells, was drilled in 1889, and the output of the state increased from 119,448 bbls.