Bank Audi looks after his money - Raymond Audi is his brother - but Mr Smith's mind is on the great generator with its new $5,000 (pounds 3,300) silencer just off Sadat Street.
Israel's June air raids destroyed two Lebanese electricity switching stations and whenever Beirut's rationed current is switched off, Smith's own little generating station must kick into life to protect the milk, juice, meat, cheese and yoghurts lining the shelves of what is still called "Smith's Supply and Trading".
It may sound colonial, but there is a bit of the old empire in Beirut's best-known grocer. He's the son of Ani Sarafian - an Armenian whose parents sniffed the political dangers and left the present-day Turkish city of Diyarbakir just before the Turks started their 1915 genocide - and Colonel Sidney Ogden-Smith, one of Britain's last mandate army officers in Palestine.
But apart from the name and punctuality - up at 5.30am, listening to the BBC at 6am, in the shop with his 57 staff prompt at 7am, "put to bed" (as he has it) by 9pm - Mr Smith is all Lebanese, a cynical, shrewd businessman with a wicked humour, a love of the good life and a constant fascination with human folly.
And this being Lebanon, the emergency generators make a profit because Smith leases his power output to 175 customers.
Some of them shop in his store to buy the 1,200 baguettes from his bakery - the Lebanese passion for French bread an inheritance from the country's love-hate relationship with France's post Great War mandate.
Mr Smith watches them arrive from his eyrie on the first floor. He looms over customers and check-out desks like a dangerous owl, eyes moving across the top of steel-framed glasses, distracted only by his battery of phones. His conversations are in French, Arabic, English - he is the last of his family to speak Armenian - and sometimes they are a little testy. Calling up creditors is routine.
ON WEDNESDAY, Raymond Audi insists that Mr Smith accompany him to hear Placido Domingo at the Beit Eddine festival. Mr Smith loves the music, hates the night-time journey back through the Chouf mountains with their gorges and hairpin bends.
More than 5,000 opera lovers are trying to leave the small town with its narrow roads and 19th-century stone buildings at the same time. Hundreds of drivers, all hooting at the same time, 10,000 headlights trapped in alleyways: Lebanese gridlock. They get back to Beirut by 2am. Three hours' sleep before opening the store.
ON THURSDAY, his staff find another shoplifter; there's one attempted theft almost daily. "Dishonesty is going up all the time," Mr Smith says. "It's a lack of the morality that disappeared over the years of the war, accelerated by the decline in purchasing power of all customers.
"They're poor people, rich people, young and old. Our personnel manager caught one of our regular customers - she'd taken a couple of soap bars and shampoos. We asked her to put them back. She said she was sorry and blushed and left the store.
"Usually people go for more expensive things like cosmetics. We had a woman who came in and hid a bottle of Dom Perignon under her skirt. We had to stop her - it's $175 a bottle."
Over the road, Mr Smith's 22-year-old son, Nael, is working in the family's latest venture, a cyber-cafe, computer mall and video store rolled into one. His older boy, Tareq, will run the place. Mr Smith's wife, May, is masterminding a bookstore up in the mountains at Faqra, beside Mr Smith's other supermarket. He knows how to expand business. And how to relax.
FRIDAY LUNCHTIME and, like most days, Mr Smith mounts his Yamaha 400cc trail bike for the three-minute journey to his boat at the St George club. There is cold beer in the icebox, Pavarotti on the CD player, his own jetski to visit other beaches. "Biking is the only sensible way to move around town in Beirut's traffic jams," he says.
Tareq takes his travel more seriously on a Harley Davidson 1400cc Fat Boy, "six times as expensive as the Yamaha and twice as large", Smith notes with a sharp glance at his son.
ON SUNDAY, Mr Smith will take the boat across the bay to Jounieh, mooring off Chez Sami's fish restaurant where a boy ties the boat to an underwater buoy. Mr Smith wades ashore like a Roman emperor to order his first arak of the day. It was not always so smooth.
He was kidnapped in 1978 by gunmen who asked for $5,000. "I told them I didn't have the money," he says. "Then one of them shot himself in the foot with his pistol and they decided I was too much trouble and they let me go. The kidnappers were pretty unprofessional in those days."
ON MONDAY, he'll be back in the eyrie, contemplating human mendacity but also the problems of his customers.
"They come to tell me they've lost their dog or their cat is sick, great people who've been very loyal to us over the years. One man came to tell me his wife had left him and asked for advice. I said he should let her go because she'll come back in the end. She did."
I realise I need to send my photograph of Mr Smith to London. And of course, Nael sends it to The Independent from the cyber-cafe. The bill will come next week. And yes, I promise to pay.