Meteorological Observations at the Cape of Good Hope

One of the most important scientists of the 19th century, John Herschel is primarily remembered for his astronomical work. It is to complete a catalogue of astronomical observations of the Southern Hemisphere that Herschel traveled to South Africa between 1834 and 1838, but he also studied the local flora, illustrated by his wife, Margaret Brodie Stewart, an excellent watercolourist.
Meteorological observations are essential to astronomy, he notes at the bottom of the page how his instruments were calibrated and explains his notations.