The first series, starting with the hyena tamer (!) depict the animal trainer Henri Martin from the first half of the 19th century.
Intermission consists of 'Absolute Zero' about (or for) Professor WJ de Haas (a physicist I think) - an undated political print by Leo Jordaan.
The sketches below are by Barend Hendrik Thier (~1743-1811), a Dutch artist about whom I didn't find much in the way of information. There are a few scenic watercolour paintings of his around online and the RijksMuseum recently purchased a dozen of his other sketch albums.
"The Atlas van Stolk is a large collection of prints, drawings and photographs documenting the history of the Netherlands, brought together by the Rotterdam timber merchant Abraham van Stolk (1814-1896). The collection was continued by his heirs and, since 1967, by the Rotterdams Historisch Museum. It contains illustrated books, broadsheets, catchpenny prints and cartoons, posters, old board and card games, as well as maps, prints, drawings and photographs, all illustrating historical events and daily life in the Netherlands up to the present day.*"There are more than 35,000 images online from the collection. The sparse homepage leads ('collection' & 'search the collection' then 'Atlas van Stolk') to the database proper, which seems a little clunky at first but is actually quite powerful in a logical metadata sort of way, and allows at least english and dutch input. There is an example 100 images for an initial browse and you can search by index or free form (I think the latter is actually much faster. Try 'topography' or 'amsterdam' or 'caricature' for instance).