Logs were sold to sawmillers from State forest from 1 July 1974 in cubic metres (true volume). Previously sawlogs had been sold on the basis of Hoppus volume. This simple device with two rotating wheels enabled staff in FCV offices to rapidly calculate log volumes from measurements taken in the bush of log girth and length and recorded on paper log dockets. From the early 1980s automated systems became available with the advent of cheap electronic office calculators and simple computers. An early manual device that was superseded by electronic calculatorsOffice Device Twin rollers used to quickly and simply calculate true log volumes using measurements of girth and length. An allowance could also be made for pipe defects. The top roller was for larger diameter logs.forest measurement, forests commission victoria (fcv)