The Last Bath's On You

For over 1,300 years, no-one noticed the lead-lined Roman Great Bath built on Britain's only hot water spring. Even, apparently, as they bathed in it. Fri 16 December 2022

Re-discovered in 1878. Source: Carved Gems Found in Roman Bath

From Carved Gems Found in Roman Bath:

... employees brush algae and sludge from the original Roman lead lined floor of the Great Bath as it is drained of 250,000 litres of hot natural thermae spa water as part of a spring cleaning operation

Sited below modern street level the Roman Baths built in AD76 and which take water from Britain's largest thermal spring, contains one of the best examples of a preserved Roman bath complex in Europe. Accidentally re-discovered in the 1800s, the steps and lead lining of the Great Bath are over 2000 years old

From The Story Behind the Roman Baths in Bath

It was in 1878 that Major Charles Davis – the city surveyor architect – discovered the Roman remains of the baths

Apparently, the Victorians immediately knocked up a Roman-looking bath-house around Davis's discovery:

The Great Bath - with brand new Roman bathhouse - allegedly photographed between 1890-1905 Source

The column bases were the only surviving Roman structures. The rest is 1890-1905 'Romanesque'.

So the orthodox claim is:

  • Age of the Great Bath: AD 2022 - AD 76 = 1,946 years
  • Year the Romans abandoned the Great Bath: approx AD 440
  • Period during the Great Bath was 'lost': AD 1878 - AD 440 = 1,438 years
  • Period between rediscovery and Roman bathhouse rebuild: AD 1890 - AD 1878 = 12 years

But when we look at the documented history of Bath's baths and the three springs that feed them, things turn murky.

From The geology of the hot springs at Bath Spa, Somerset, Dr Rameus Gallois, 2006:

The three springs that emerge under artesian head at 45-46ºC beneath and adjacent to the Roman Bath in the centre of Bath Spa, Somerset...

The extent of [the Roman] walled city remained little changed until the end of medieval times (Figure 1):

Figure 1 is this 1588 map:

The bath is identified as 'A The Kings Bath'. Source: The geology of the hot springs at Bath Spa, Somerset

It's not looking very lost to me. Perhaps it got lost after 1588.


From Bath - Hot Springs:

Bath was, in fact, charged with responsibility for the Hot Springs in a Royal Charter of 1591 granted by Elizabeth I

And from The geology of the hot springs at Bath Spa, Somerset, Dr Rameus Gallois, 2006:

the first national hospital in Britain, the Royal Mineral Water Hospital, was founded in Bath in 1738.

And from Bath, Somerset:

In the 17th century, claims were made for the curative properties of water from the springs, and Bath became popular as a spa town in the Georgian era. (1714 to c. 1830–1837)

So, how old are you really? Source: Jupiter Ascending

In any case, it really would have been hard to lose Bath's bath: its water is by far the hottest spring water in the British Isles. And when Gallois says:

the three springs emerge under artesian head

he means:

if the springs had not been diverted into baths, they would jet up to about 9m (30ft) above ground.

You'd notice them.

Also inexplicable is how Bath's springs emerge in such a tiny area. And from what.

From The geology of the hot springs at Bath Spa, Somerset:

Information on the detailed geology beneath the hot springs remained relatively sparse until 1977-78 when two significant events occurred. First, subsidence at the Roman Baths prompted urgent remedial action. A pattern of site-investigation boreholes was drilled that enabled Kellaway (1991b) to determine the 3D shape of the top part of the ‘spring pipe’. A subsequent investigation to stabilise the Roman buildings at the Cross Bath revealed a similar structure.

the hot water emerges from ‘spring pipes’, conical structures infilled with mixtures of river gravel and clasts of Triassic and Jurassic rocks. Most significantly, the Stall Street Inclined Borehole showed that this loosely compacted debris extended down to the Carboniferous Limestone in partially filled cavities

In other words, the three springs rise through three separate conical holes in limestone. Each is filled with gravel. At the bottom of one of them, CCTV investigation found part of a Roman tile. The holes are 70m (230ft) deep.

Quite the diggers, those Romans.

From The geology of the hot springs at Bath Spa, Somerset:

Several hypotheses have been published to explain all or part of the mechanism that gives rise to the hot springs.

And then, sparing you the technical details:

The model is in accord with the chemical results, but not with the known geology.

The artesian heads at the hot springs remain problematical, but are unlikely to be due to the difference in topographical height between the Mendips and the springs. Artesian heads are absent c. 2 km west of the hot springs where the Westbury Formation, the aquiclude that confines the head at the springs, comes to crop. Artesian heads are also absent from the Carboniferous Limestone where it is confined beneath the Westbury Formation in the Alice Park (ST 7650 6659) and Tuckingmill (ST 7640 6160) boreholes, 2.5 and 3.5 km from the hot springs respectively. In our present state of knowledge, the most likely explanation of the artesian heads is that they are a local phenomenon related to the high-relief topography of the Avon Valley at Bath.

Neither the Mendips Model nor the fracture hypotheses explains why the hot springs are unique in Britain nor why they are confined to such a small area.

Gallois then examines the pros and cons of the various hypotheses and concludes:

However, none of these hypotheses explains why the hot springs are confined to such a small (20 x 80 m) area.

Perhaps the answer lies in a fact that geologists won't consider in relation to Bath's mysterious hot water.

From The geology of the hot springs at Bath Spa, Somerset:

The discovery in 1903 of significant concentrations of radium salts in the spa waters led to the belief, at least temporarily, that this was the active beneficial ingredient and a ‘radium inhalitorium’ was constructed. It closed after the accident at nuclear power plant at Seascale (now Windscale) in 1959.

Summing up Bath's baths:

  • Why does anyone claim the lead-lined baths were lost for 1,400 years?
  • How were the three gravel-filled conical voids created?
  • How did a Roman tile find its way to the bottom of one of them?
  • Why does this tiny area produce Britain's only hot ground-water?
  • Why is the water radioactive?
  • Why did the Romans line the bath with lead?

Somebody must have answers:

A fusion of technology in-jokes. Source: History of Britain

The Great Bath, Bath

© All rights reserved. The original author retains ownership and rights.

More in category: Misunderstood Technology
More by tag: #geology, #radiation