Today in 1770 the adventurer James Bruce reportedly discovered the source of the Nile in north-west Ethiopia.

Bruce travelled extensively through north Africa in search of the river's source, even becoming a respected friend of the Abyssinian royal family, and in 1790 he published a lengthy account of his travels. Due to a self-confidence bordering on arrogance he made many enemies, notably Samuel Johnson, who criticised his writings and cast doubt on their veracity. Very little was known about Africa at the time, and this lent credence to the claims that Bruce had embellished his account. Although he turned out to be mistaken about the source of the Nile, the descriptions of his travels in Africa have since proven largely accurate.

On this day in 1797 Sir Charles Lyell, the important Scottish geologist, was born. In his seminal work, Principles of Geology, he challenged the dominant thinking of the time which was based on the biblical viewpoint.

Building on the ideas of James Hutton, by careful observation he concluded that the Earth's physical features and its inhabitants were the result of continuous physical and chemical processes occurring gradually over long periods of geological time. Lyell's theory was revolutionary and infuriated the devout majority.

He later supported Charles Darwin's ideas about evolution.

Today's recipe: a classic, creamy carbonara.