# When was the earliest use of log-log plots to demonstrate power-law behavior?

After reading this answer and writing this comment, I decided to ask this question: When and where was the earliest known use of a log-log plot to demonstrate power-law behavior?

Napier introduced the logarithms in 1614, and Gunter invented the slide rule somewhere in 1620s. One might think that log log plots came soon after, but no. According to The Age of Graphical Computing: "In 1844 Leon Lalanne succeeded in linearizing the curves $y=x^p$ by plotting the first log-log plot in history, thereby creating his Universal Calculator, chock-full of lines for common engineering calculations and capable of graphically computing formulas in powers or roots of x ( or of trigonometric functions in x) with ease... Lalanne envisioned copies of his Universal Calculator posted in public squares and business meeting places for popular use". Lallane's successor, d'Ocagne, also credits him with the invention of logarithmic graph paper. The first link has a nice image of Lalanne's Universal Calculator, which looks like a fanciful version of it.