The Line Graph. It was Playfair’s older brother—who required him to record every day’s temperature and record them a la the naturalists of the day—who inspired the line graph.

The graph shows spikes and drops in temperature over the past 9,500 years, charting how much higher or lower each year’s temperatures are than the average temperature over the entire time period.

Source: “A 485-million-year history of Earth’s surface temperature”, E.J. Judd et al. Temperatures are averages for geological periods. Shaded area shows values with a 68% probability.

By Peter Andrey Smith . The neoclassical face of the Time and Temperature Building rises 146 feet over downtown Portland’s Monument Square. Through the building’s entry on Congress Street and past the ...

A line graph could be used to show the changes in a country's employment structure over time. This graph shows that in the post-industrial era approximately 11% of employed people work in primary ...