Tosca-at-Covent-Garden is a commodity, like bacon-for-breakfast - a pricier commodity, to be true, at officially up to £229.50 a seat, but in both cases people want to get what they expect. For the final performances next month in this summer revival, with the megastars Angela Gheorghiu, Jonas Kaufmann and Bryn Terfel, all seats are sold, with touts on eBay offering a pair of amphitheatre seats at bids over £300.

It would take the cunning of the insane to invent the British railway network. Privatised 18 years ago, it offers the worst of all worlds - persistent overcrowding and cancellations, outdated rolling stock and fares rising vertiginously as services grow steadily more uncomfortable, while the taxpayer still has to stump up billions to keep this wheezing Heath Robinson nightmare functioning at all.

Problematic in performance in a way that the “problem plays” simply aren’t, Shakespeare’s Roman plays remain some of his hardest to stage satisfactorily. Updated versions too often turn into Magritte-esque fantasies of identikit, suited politicos, while the togas of more traditional approaches can feel absurd, unavoidably laden with satiric or Hollywood associations.

For quirky authority in Shakespeare, Kathryn Hunter is surely up there with Mark Rylance. Her production of Pericles was one of the two best things I’ve seen at the Globe – Rylance in Twelfth Night being the other - her characterisations of Lear and Richard III as compelling as any. Hunter plays Cleopatra as a regal, shrewd eastern cousin of Katherina and Beatrice, making the case for a very human prose which would no doubt work better if the production around which she snakes and sharptongues found a little more poetry in other quarters.

Derek Jacobi (b 1938) grew up in Leytonstone. His father was a tobacconist, his mother worked in a department store. Although he entered the profession in the great age of social mobility in the early 1960s, no one could have predicted that he would go on to play so many English kings - Edward II, a couple of Henry VIIIs and Shakespeare’s two Richards - as well as a Spanish one in Don Carlos. This month he prepares to play another king of Albion: Lear, against which all classical actors past a certain age must finally measure themselves.

Mount Vesuvius blew its top in 1631, spewing molten lava into the sea and filling the air with ash clouds that reached as far as Constantinople. The eruption and accompanying earthquakes killed 3,000 people and caused widespread devastation, all of which made a lasting impression on the 16–year-old Salvator Rosa. As an artist he was to specialise in darkly tempestuous landscapes filled with menace in which small figures are dwarfed by towering cliffs, or beset by bandits, while storm clouds gather over ruined buildings and blasted trees.

To mark Pope Benedict’s controversial visit to Britain next week, the V&A have mounted an exhibition devoted to four of the 10 tapestries Raphael designed for the Sistine Chapel – the first time they’ve ever been seen in this country. Depicting the Acts of St Peter and St Paul, these bright, vivid works were made to hang on the lower walls of the Vatican’s principal chapel, below the older Michelangelo’s ceiling fresco

One of the downsides of the international media’s obsession with the crimes and misdemeanours of Silvio Berlusconi and his make-it-up-as-you-go-along style of government is that anything that doesn’t fit in with the overall narrative of the crazed, corrupt media mogul destroying an otherwise magnificent, well-organised country, tends not to make the headlines.

I always liked that line in the 1960 Spartacus movie when Spartacus's lover Varinia (Jean Simmons) is bidding a silent farewell to the crucified rebel gladiator. "Tell da lady no loidering," growls the Roman sentry standing guard nearby. I can't tell you whether the line will appear in this new and lurid rehash of the Spartacus legend, though if it does it won't have quite the same Bronx ambience about it since most of the accents are from the Antipodes, the series having been shot in New Zealand.