Determining Mean Effective Pressure from indicator diagrams
Notes: "The Bushnell-Coffin planimeter (named after John Coffin) is similar to the Ashcroft Averaging Planimeter in that it is a self-contained system, with an aluminum plate holding all the pieces, a card pad for the planimeter's tracing wheel to run on, multiple scales for different indicator spring strength, and a holder for the piece of paper with the indicator diagram. The weight for the planimeter is missing, and the tracing point is badly bent. "
