Back in Britain (I write this on the Elizabeth line from Heathrow) it seems I’ve arrived too late to pre-empt the story that botanists have brought to Britain a batch of the rare and recently discovered Wollemi pine, in hopes of their survival here.
The botanists say that Australia, where the tree comes from, may become inhospitable for Wollemi pines due to climate change. Well, Australia may be too hot but Britain is probably too cold or too sunless. I planted one in a sheltered spot in Derbyshire about 15 years ago. The first winter killed it. There’s another, planted in the lovely Embankment Gardens near Embankment Tube station in London. It struggles, though the wide Thames moderates ambient temperatures.
It’s hard to believe anywhere else in Britain will prove hospitable. Just possibly the Isles of Scilly but I wouldn’t risk a hundred rare specimens outdoors in our climate. These refugee trees may have to pitch camp in the glasshouses at Kew.
Rolling stock
A stopover in Doha on Monday night may — may — have proved that my boyhood daydream wasn’t crazy after all. Qatar has built an impressive driverless underground line, and we took it from the airport. Watching from the back window of the last carriage, we appeared to go downhill out of every station and uphill into the next: a kind of gentle rollercoaster. In my youth I drew up such a plan for Tube lines, figuring that since going uphill decelerates you without brakes and going downhill accelerates you without an engine, a line shaped like a rollercoaster with stations at each peak would require very little by way of locomotive power and save all the energy that is wasted as the heat dissipates from a braking system.
In theory (absent wind-resistance and friction from the wheel-bearings) a train could run without any need for power — just a little push at the beginning of the journey. Of course, in practice you’d need some extra locomotion to hurry up acceleration, and a touch on the brakes to hurry up the stops, but still the energy saving could be enormous.
Advertisement
Someone once told me that some London Underground tunnelling does employ my theory but I’ve been unable to verify this. Qatar, essentially flat, would be ideal. But is this what they’re trying? I’ve googled for ages but found no mention: “rollercoaster” as a search term yields the wrong results. Could any railway engineer among my readers enlighten me?
Apple-pie island
It all seems so far from Pemba Island. Heard of it? Zanzibar’s lesser-known small sister lies some 50 miles further up the east African coast. About 40 miles long, Pemba’s a warm, hilly, coral-strewn, lush little world of its own, ringed by mangrove swamps and the occasional sand beach. There’s an African (mostly Muslim) population but very few visitors. Pemba is known best for spices: it is one of the world’s principal sources of cloves, the dried flowers of a small tree. In just one wooded smallholding we were shown cinnamon trees, vanilla vines, lemon grass, pepper vines, cardamom, mangos, breadfruit, cacao and a pineapple. In the clove harvest, groundsheets strewn with the spice dry in the sun by the roadside, bathing the island in the aroma of a baked apple pudding.
Blue yonder
There’s a modest lodge on a beach where we stayed before flying to Britain and on Saturday we ventured upon one of the strangest walks of my life. About half a mile offshore stretches an unbroken reef. Across the flat lagoon it creates you can hear the distant roar of ocean breakers on the coral. The lagoon fills and empties with the tides and at low tide is seldom more than knee-deep, the water warm as a bath. In flip-flops for protection from broken coral you can walk out to the reef, where the ant-like figures of fishermen and shellfish gatherers can be seen.
It took ages. Sloshing forward in a hot breeze, we waded towards two horizons: the mid blue of the sky was underscored by the deep blue of the ocean. That deep blue ocean was underscored by a thin black line of reef. Beneath that line, the lagoon was pale turquoise. Three panels, three shades of blue; and all the dividing lines straight. We were walking into abstract art.
