Discussion on “recent improvements in electric lighting of steam railroad cars” (Lanphier), San Francisco, Cal., Sept. 16, 1915. (see proceedings for August, 1915)

George R. Murphy: For a number of years the ampere-hour meter has been used with satisfactory results as an automatic means for interrupting the charging circuit of a battery at the end of charge. Allowance for the necessary amount of overcharge has been made either by adjusting the meter to run proportionately slower during charge than during discharge, or in some case by manually setting the pointer of the instrument ahead by some pre-determined amount just before the beginning of charge.