On 31 August 1946 the first Edinburgh Film Festival opened.

The festival was officially opened on this date by the Lord Provost at the Playhouse Cinema. The festival was originally known as the International Festival of Documentary, but has now grown to become recognised as one of the great worldwide film festivals.

On 31 Aug 1721 Scottish mathematician, John Keill, died. Keill was elected a Fellow of the Royal Society in 1700 and Savilian Professor of Astronomy at Oxford in 1712.

He acted as a propagator of Newton's philosophy and argued against Whiston and others. He claimed that Leibniz had plagiarised Newton's invention of the calculus and he served as Newton's avowed champion.

He also wrote on forces between particles and on theories of the origin of the universe.

Today's recipe: mackerel served with in-season greengage chutney is a cheap and healthy light lunch.