Inspired by Brian’s expedition last week to General Roy’s southern baseline cannon I decided to find its northern counterpart for hopefully my last lockdown local ride.
The baseline was an accurately measured distance between two points which could be used as a reference to calculate the relative position of any other point in Britain. It formed the basis of the first systematic survey of Britain, which would later become the Ordnance Survey.
The southern point which Brian visited was in Hampton and the baseline stretched across what was then open country to near the Great West Road. The latter point was probably chosen by Roy to be conveniently close the road from London to Windsor for inspection by King George III who was funding the project, and which he visited on 21 August 1784.
Despite its significance to the OS, the southern point is unmarked on their maps today. The northern point is marked, rather cryptically by the single word “Cannon” near the northern end of the airport tunnel. Unfortunately, the diligence of Roy’s historic surveying is not matched by the clarity of OS contemporary cartography, so I rode around in I circles in the rain before finding the said cannon, nicely preserved in a little garden near the HM Customs building.
Having satisfied my curiosity I was back on the Heathrow inner ring road, not normally a destination for touring cyclists, but eerily deserted of traffic, which made for a calm, if damp, ride. Probably it will remain deserted for a while, given the present slow global progress against Covid.
George III has a mixed reputation today, but in his time he was an active sponsor and participant in scientific endeavour, which has left several monuments in our area. He had Kew Observatory built in the Old Deer Park Richmond so he could observe the transit of the planet Venus in 1769. Today it’s a private house, I believe unoccupied, perhaps because it doesn’t provide the kind of privacy from public view which someone who could afford the rent would seek.
The last stop on my ride was the obelisk on Putney Heath, close by the old Portsmouth Road. It commemorates the time in 1776 when king George was persuaded to take breakfast in the upper floor by the inventor of a “fire-proof” house while the ground floor was set ablaze. Doubtless a risky undertaking, but George clearly chose his projects well, for he reigned for another 44 years, and left a permanent memorial too.
1 comment:
Well done Dave. Perhaps we should ride some of these roads and visit these places as a group before normal service is resumed at Heathrow. Teddington to Stanwell Moor via the cannon anyone?
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