The aim of that is to stop unauthorised people from drinking the contents (in particular, "servants and younger sons getting at the whisky"),[1] while still allowing them to be on show.
[3] Very few Betjemann examples survive in complete condition; those that do are generally sold at auction for sums in the thousands of US dollars.
Later models, in completely different styles, were also called "The Betjemann Tantalus"[1] even though no cabinetry was present and they were not made at the Pentonville works.
Betjemann was the grandfather of the poet John Betjeman, who in Summoned by Bells called it the source of the family fortune.
[5] In Elizabeth Bowen's The Last September, Livvy Thompson's father is described as a despondent, mild-mannered teetotaller who had "half a decanter of whisky in his tantalus," but he had lost the key.