With this tool you can create a timeline for sets of items
in the database
First select a category (e.g. illustration)
and optionally a location (e.g. France)
of the items you want to include in the timeline.
Then click the "Graph" button to create the timeline.
Each bar in the timeline represents a period of time. The height of
the bar represents the number of items in the database that fall
within that period. The color of the bar indicates the category of
the items. The legend on the right shows the colors for each
category.