Who first used a bar graph of means? I've read a lot about Playfair and the history of graphics. However, I have not discovered who was the first to create the now popular yet information-poor bar graph of means. Anybody know?
 A: I rather disagree that the bargraph, or specifically a bargraph of means, is information poor. Used in tandem with error bars, it can be equivalent to a forest plot to allow approximate inference and verification of consistency, as well as presenting the scale of effect so as to allow the viewer to compare effects both on a difference scale and on a log scale, depending on their perception. That's not to say that graphs cannot be used badly, and in ways I can't anticipate fully or even describe... but to name a few, 1) using truncation/omitting the origin, 2) omitting a y-axis or labeling it, and/or forgetting or using the wrong units 3) using superfluous dimensions like width, color, or 3-dimensions to obscure the effect of interest, 4) not mentioning how means and/or SEs are calculated and whether the error bar is 1 SE or 1.96 SEs. Those problems could be encountered in virtually any plot and serves as a reminder: it is not the tools, but their misuse, that contribute to a bad reputation. I would be interested to know how you might propose another general approach.
A very early example of bar graphs of means comes from Florence Nightengale who independently pioneered great dataviz tools. Here she presents death rates per 1,000 which, under a counting process like Poisson a rate is also a mean accounting for an person-year offset. This image dates to 1858. Seeing as there are no other answers, I'm almost certain an earlier verifiable source could be found, but this is one very early example to celebrate an influential figure in data visualization.

https://www.theguardian.com/news/datablog/2010/aug/13/florence-nightingale-graphics
