I start with cafe complet in the Cafe Melies, inside the French Institute (Queensberry Place, SW7). This is the haunt of French teenagers studying at the Lycee next door: they make a terrible noise and strike an authentic note. The French aren't much interested in morning newspapers (Le Monde only comes out at midday), so I shall be keeping half a lustful eye on the beautiful kids, half on my copy of Benjamin Constant's novel of dangerous passion Adolphe. Then I shall saunter idly over the road to Bute Street, in which is concentrated The French Bookshop (for papeterie and the latest winner of the Prix Goncourt), the Bute Street Boucherie (for boudin, andouillette and Toulouse sausages), and the delicatessen La Grande Bouchee (for foie gras and truffles). I'm not buying anything: just looking.
Then I stroll across Hyde Park to the Wallace Collection (Manchester Square, WI) - far superior to its Parisian equivalent, the Musee Jacqumart-Andre. Room 18 is a perfumed paradise of Boucher, Fragonard, Watteau and Greuze: but somehow its deliciousness stimulates invincible thoughts of lunch. Where more convenient than Villandry (89 Marylebone High Street, WI), a simple and elegant dining room at the back of a magnificent traiteur?
Post-prandial stupor sets in: I take a bus down to the French church in Soho. Notre Dame de France (Leicester Place, WC2) is decorated with murals by Jean Cocteau: contemplating their airy charm, I fall into a doze and dream of the wretched exiles from the Paris Commune who flooded into this part of London in 1871, fleeing the prosecution of the savagely reactionary Third Republic; here too in 1872-3 lodged the poets Verlaine and Rimbaud, sodden with drink and locked into their mutually destructive love-hate affair.
Rudely awakened as early evening mass begins, I walk down Piccadilly, past the Ritz, most ostentatiously gilded and Parisian of London hotels, back to the French Institute, where I peruse its excellent programme of movies and lectures and hope beyond hope that the morning's love object, some exquisite creature from the Lycee, will be there too. No such luck: so I step over to the crowded bistro Le Bouchon (Fulham Road, SW7) for steak, frites and another half an eye on Adolphe.
I've been drinking too much coffee to think about bed, but where next? Ah-ha: Victoria, and the last train to the Kentish suburb of Petts Wood, about half an hour away. Five minutes from the station at 41 Birchwood Road stands a pseudo-Tudor mansion of thoroughly English, if not Betjemanesque stolidity. This was the unlikely home of General de Gaulle during his wartime exile - from here he led Free France. It makes a wonderfully unlikely climax to my day of flanerie.
Rupert Christiansen's Tales of the New Babylon: Paris 1869-75 is published this week by Sinclair Stevenson at pounds 20