Which of the following is not considered a log scale?

The Franklin scale is not considered a log scale because it does not operate on a logarithmic basis for measuring and converting wood volume. Instead, the Franklin scale measures board feet based on certain dimensions, primarily focusing on the actual board's size without converting it to a logarithmic format.

In contrast, the Doyle, Scribner, and International ¼ scales are all log scales that use logarithmic functions to estimate the volume of timber based on the diameter at breast height (DBH) and length of the logs. These scales are created to simplify the calculation of timber volume and account for various factors like the taper of the tree and the standard cuts of logs. Each operates on principles that relate dimensions to logarithmic values, thereby allowing for quick estimation of wood volume.

Understanding the differences among these scales is important for those in the timber industry, as using the correct volume estimate can affect valuation and pricing decisions in timber sales and management.