Into spring and BST, and despite the near six-week gap and the galloping strides evident on the plot, I still naively expected this to be northside of the river. For the first time I cycled down, a lockdown reacquaintance, and parked the Santander bike behind old Billingsgate after a 10-minute pootle down the blue CS3. When I got to the riverbank it was immediately clear I’d seriously misjudged it. The Sun sat far, far above the Shard:
People say that the evenings get lighter so quickly at this time of year. They’re not wrong. Between 24th February and 1st April, 36 days, the Sun moved from a peak of about 30 degrees to about 44 degrees. That’s a 14 degree swing. That’s about the same as the change to February 24th from the winter solstice just before Christmas, which isn’t that different to the rest of the month of December. Say 72 days. Twice as fast in spring. Seasons change.
On the plus side I’d overestimated how long it would take me to cycle there, so I didn’t have to run southwards down the bridge in a mad spring dash, and I still got level with the shadow with a few minutes to spare.
But now I was back at the late summer’s problem. How to put on a map a shadow on a river? I’d tried GPS and it put me in the Thames. I’d tried photos of the surroundings but it was far too confusing and complicated. This time maybe the old divers’ trick of lining up two pairs of onshore landmarks to find a wreck?
So from the bridge the shadow’s tip was just north of a line connecting the north tower of Tower Bridge with the bridge of HMS Belfast. That’s one pair. Scooting south to the walkway I could just about see, three minutes later than 1pm, the shadow’s gap pointing to the right side of Adelaide House. Maybe just enough to triangulate with…
It’s also worth noting that the Sun is at pretty much 45 degrees according to the plot, maybe just shy, which means the shadow of the Shard is the same length as the Shard is high, 309.6 metres to its tip, so probably about 305 to its cleft. Some combination of all this triangulation will surely help place this one…
Shard Analemma 