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By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

2. For one thing, the site in Trewsbury Meadow has totally dried up – fair enough, it was always seasonal. But half a mile downstream is Lyd Well, in the area marked on old maps as Thames Head. But alas this was bone dry today too. https://t.co/zHVJxksJdL

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

3. The fons et origo, as it were, of historical accounts that this Thames Head is the source go back to John Leland in 1542: “Isis riseth at three myles from Cirencestre, not far from a village cawlled Kemble, within half a mile of the Fosseway, wher the very head of Isis is”. https://t.co/n4MDanLLBl

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

4. But hang on: in 1598 John Stow wrote “this famous streame hath her head… about a mile from Tetbury, neare unto the Fosse, (an highway so called of old)”. But Thames Head is 6 miles from Tetbury, even as the crow flies. I’ve found a nearer candidate, only 2 miles from Tetbury! https://t.co/ARIdLaeOhb

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

5. This is near the ultimate source of the Swill Brook (also dry alas). Its very brief Wikipedia page quips about it being bigger than the Thames where they meet. Er, hang on! Bigger? Also pictured here are where they meet, the weedy Thames thereafter and the lily-padded Swill. https://t.co/cOSTjyfu0C

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

6. But as well as bigger, it’s longer! From Lechlade to Thames Head is 33.7km (I’ve measured it using specialist OS data). From Lechlade to the Swill’s source is… 39.5km! So apologies to Old Father Thames in Ashton Keynes here, but you’re in the wrong place, mate. But wait… https://t.co/VPumMUJTKY

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

7. There’s even a further possibility mentioned in @PaulWhitewick’s excellent recent thread and video about some of this, referring to a leak from the Thames and Severn Canal, further up than Thames Head. twitter.com/PaulWhitewick/… https://t.co/X3RXVSymZU

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

8. As Paul mentions, it’s an open secret that the *real* source is Seven Springs, known as the mouth of the tributary River Churn. Here it is, bubbling happily, a whopping 52.7km from Lechlade & making the Thames waters longer than the Severn. But… there’s a further source yet! https://t.co/cwFPsghCEp

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

9. A bit W of there is this pond at Ullenwood’s college & a nearby stream – bubbling happily, a whole 54.8km from Lechlade, and feeding into the ‘Churn’. Thames Head is so utterly geographically – and even historically – wrong! Ah well: it won the gong, so the ‘source’ it is. https://t.co/mRwla0vPTA

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

10. Even the source of the tributary Coln is 49.km from Lechlade. Thames Head isn’t even technically in the top 10 distance-wise! This map (OS Open Rivers data) shows A: Thames Head B: Swill Brook C: River Coln D: Churn (Seven Springs) E: Churn (Ullenwood). Bye! https://t.co/cjlw3tGS27

By: Andrew Chapman

Andrew Chapman — Sun, 17 Sep 2023 13:54:38 +0000

@threadreaderapp unroll