Flamsteed's Well

Flamsteed's Well - a telescope located in a 100-foot deep brick-lined shaft on Observatory Hill - came into operation during or soon after November 1677; the lower 15 feet or so were unlined where the shaft entered chalk. After endlessly debating the available evidence in the manner of Sherlock Holmes, I have concluded that there is no irrefutable piece of information that can tell us when the shaft was originally constructed, and it could perhaps predate Duke Humphrey's activity on the site in the early 1430s. Even the idea that Flamsteed had the shaft specially sunk cannot be ruled out, although it would be bizarre for him not to mention it. The fact that it was not located on the "meridian" of the Octagon Room - which as convincingly proposed by Graham Dolan was the notional meridian of Flamsteed's era - carries little weight in the debate.

The original purpose of the shaft is obscure; rambling speculation is no substitute for hard historical evidence.

What we do know from contemporary illustrations is that a spiral staircase was installed, and the viewer reclined on a couch at the bottom to make celestial observations. As candles or oil lanterns were the light source, and ventilation was insufficient, air quality would have become very poor over a number of hours, with rising CO₂ and CO and falling O₂. Even if Flamsteed had extinguished his CO-producing yellow flame light source to achieve the desired dark viewing conditions, CO₂ would have continued to increase and O₂ to decrease. With daily use, the poor air would have lingered at the base of the shaft, eventually improving through barometric draughting if nobody went down. At ground level a small octagonal building kept the weather out and also probably housed the upper lens. In the first picture below (about 1680), this octagonal structure is clearly visible standing alone some distance to the right (South) of the observatory complex. The second and third pictures, which have a different viewpoint, put it more South East of the observatory.

Click for a large version (252k 1280x770)


A very similar version of the picture above; the vegetation is the main difference. (Mary Evans Picture Library)

↑ View from the roof of Flamsteed House; the well is at the bottom right corner. Click for a larger version (932k 1200 x 773)

↑ The plan that appears in Baily's 1835 biography of Flamsteed; this is supposedly an exact copy or replica of Flamsteed's own drawing. Click for a larger version (85k 580x669)

Visitors to the Observatory today will see a ring of bricks marking the supposed site of the well; the bricks mark the position of a rubble-filled unlined shaft discovered during an archaeological dig in 1965. The location of the well marked in Baily's plan of the Observatory (published 1835) fits closely (within a few metres) with this position when an overlay is done:

↑ Click for slightly larger version (246k 566 x 458)

In one bound this overlay makes a number of previous academic debates about the location of the well redundant, including the 1881 subsidence and the Lynn/Maunder letters.

The enormous difficulties with Flamsteed's well lead me to invoke the spirit of Sherlock Holmes. Ironically it's almost certain that Conan Doyle would have read Conrad's The Secret Agent of 1907, in which the character Verloc is tasked by Mr Vladimir (First Secretary in the embassy of a foreign country, by implication Russia) with blowing up Greenwich Observatory.



"You will not apply my precept," he said, shaking his head. "How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? We know that he did not come through the door, the window, or the chimney. We also know that he could not have been concealed in the room, as there is no concealment possible. When, then, did he come?"

(Sherlock Holmes The Sign of the Four)

Furthermore the two similar illustrations immediately above the plan also support the Baily location when perspective lines are projected, although the 1680 painting above them turns out to be very inaccurate - at least two different viewpoints have been combined into one image.

The absence of bricks in the shaft is extremely puzzling, unless of course they were salvaged. Why go to so much trouble? Because stripping the lining yielded around 7,500 bricks in good condition - a valuable commodity which could be used immediately (and conveniently) on site or stored until required. That number of bricks today (a reasonable quality facing brick) would cost in excess of £2,500 at your local builders merchant. The labour cost of stripping the bricks out of the shaft and then filling it would have been modest because labourers already employed within the park could have been used - much cheaper than bringing in an external contractor.

Here is a summary of the dig by F. Willmot of the Lewisham Natural History Society (my bolded text):

In 1965, the society learned of the efforts being made to locate the well, and examining the site, found that the contractors had uncovered a roughly circular, filled shaft, between 7 feet and 8 feet in diameter. This was near a spot indicated on a 19th century plan of the Observatory as being "site of Flamsteed's Well." At the request of the Ministry of Public Building and Works, the Society continued to remove the mixed infill of the "well," at the same time preserving its circular edge. At 24 feet below ground level, the Society reported to the Ministry that it would be unwise to continue deeper without further timbering.

No real evidence of any brick lining was found. No stratification existed within the well, the part examined having been filled in the 19th century. Traces of a hexagon shape within the infill of the circle of the well were noted, perhaps associated with a small six-sided building known to have capped the well in Flamsteed's time.

> The 19th century plan Willmot refers to is probably Airy's drawing, because Baily describes it (differently) as "The well, in which observations were sometimes made".

> The profile of Flamsteed's Well was circular, not hexagonal, with an octagonal structure built above it. Here's a small area of Flamsteed's own plan clearly showing the octagonal shape:


We are currently undertaking a thorough review of all archival material.

LATEST RESEARCH

>> The 1963 assertion by Laurie and Waters that "by the time Bradley became Astronomer Royal in 1742... [Flamsteed's] well telescope was filled in, having failed at an early date" is clearly impossible, because pottery dating a century later was found throughout the 24-foot depth of infill examined in the shaft. The shaft may well have been capped and covered over by 1742, but it had not yet been filled in.

>> A well was sunk in 1815, with a depth (according to what Airy was told) of 120 feet. But he points out that "the water proved bad and the well was covered in." Whether that means capped or actually filled in is open to question. We know the location of this later well to within several metres, and are investigating; it is/was located in the large garden below the Observatory.

Here are two excellent (and recent) aerial photos of the site which are very helpful in determining the viewpoints of the different historic illustrations (click each for the large version):

© National Maritime Museum

© National Maritime Museum

We have seen entrances to three culverts (17th or 18th century) at the Observatory, one bricked up and the other two choked to the roof with rubble - in addition to the remains of the covered way which led from the old Observatory to the new buildings. These culverts need to be opened up and properly surveyed/explored, as they are in the area of Flamsteed's Well. The well would certainly have made a wonderful soakaway or cess pit once it had become derelict. Opportunities for archaeological investigation at the Observatory over the years seem to have been sadly lacking.

Only two observations were ever recorded, in June and July 1679, suggesting that scientifically it was a failure, although the poor quality of the object lens (demonstrated in a 1956 test) may have been partly to blame. We know that it had become disused by 1737, because on November 3rd of that year the lens was presented to the Royal Society. The donor, James Hodgson, married Flamsteed's niece and went on to inherit some of his property; Hodgson was assistant at Greenwich 1696-1702.


↑ A contemporary cross-section through the "well". Note that the diameter of the octagon structure is smaller than that of the well; the octagon is positioned assymetrically, which would have meant that some type of bridging arrangement was needed for support. Click for larger versions (120k 187x800 & 103k 484x452 respectively)

↑ The site of the well (Nov 2009). Photographer unknown - if it's you, please contact me to be credited.

↑ Greenwich Castle, which stood on the site of the Royal Observatory, in its final incarnation during the mid 17th century.

A good analogue for Flamsteed's Well is the octagonal Vienna sewer kiosk seen in the 1949 movie "The Third Man" with Orson Welles and Joseph Cotten, which is the correct height of about 12 feet:





We have considerably more material than appears above, but are currently constrained by copyright issues; hopefully in due course much more will be added to this post.

Conduit Houses inside the park

The earliest known depiction of a conduit house in Greenwich appears in van den Wyngaerde's panorama of Henry VIII's Palace of Placentia, drawn in 1558 when the palace was still at the zenith of its architectural maturity. The little house is hardly more than a scribble, yet definitely a structure of the correct size located in the right place - the hillside where both the Standard Conduit and the Snow Well (the ventilation shaft of an unknown conduit misnamed by Webster) are located. The Snow Well was a 30-foot deep well with passageway at the bottom heading in the direction of St Marys Gate, and is/was located in a tree-lined depression some 100 yards towards the Observatory from the standard; it must not be confused with the Hyde Vale conduit, which is quite separate.

Later conduit houses built in the era of the Royal Hospital frequently pop up in views of the park: several are shown below. Without any context it's usually very difficult to link them to particular conduit passageway or access points.

Do any of the conduit houses pictured above date from the Tudor era? Perhaps. What did Tudor conduit houses look like? Have a look at this photo set on Flickr.com of Coombe Conduit, which along with two other houses (Ivy Conduit and Gallows Conduit) supplied Hampton Court Palace from 3 miles away.

Woolwich Conduits

Woolwich Arsenal had a substantial conduit system, upon which lavish sums were spent during the late 17th and early 18th centuries in a desperate effort to supply the huge demands of the military establishment. An infamous local gravel digger named Pattison was hauled in front of the local magistrate at one point after destroying part of the system and severely disrupting water flow. The main artery was called the Office Conduit (short for Office of Ordnance), and had a conduit house in Cholic Lane for many years; it's extremely frustrating that we never managed to find any of the passageway. Tower Place, the grand Tudor house that stood in the Arsenal, also had its own conduit - of unknown extent or location - although it may well have used the same spring source as the later system. Further reading on the Pattison case can be found in O. F. G. Hogg's excellent history of the Arsenal.

Rocque's map of the early 1740s clearly shows Cholic Lane and "The Spring Head". Click map for a big version (348k 654x891)

Hyde Vale Conduit

Everyone seems to have heard of the Hyde Vale Conduit, but not many people have actually been in it. The passageway (which exceeds 1,400 feet in length) starts inside the park in a cellar-like structure...

↑ Click for larger version (838k 1500 x 1245)

↑ Click for larger version (908k 1500 x 1094)
...near the Standard Reservoir building, and heads over towards the Ursuline Convent and school, passing under the roadway of Crooms Hill at a depth of some thirty feet. The height of this section can be described as lofty - about seven feet high, and wide enough for two people to pass without twisting sideways. Air shafts are encountered at regular intervals, including one that originally opened onto the sloping grass triangle in front of the convent - we surveyed and photographed a previously unknown high-level passage that leads off this shaft near ground level. This deep cut-through under Crooms Hill was probably constructed in 1696.

As the conduit nears Hyde Vale, the remains of a former entrance (via staircase) are encountered - the surface structure associated with this staircase can just be seen in a painting of Hyde Vale from around 1830 (click for a larger version 203k 1023 x 297):

↑ For more info on the staircase entrance, please see this post
Progress is now blocked by infill from modern-day electricity cable works. In the "upper" section beyond the blockage the passage is much lower and narrower, the arch having been decapitated and replaced with granite kerb stones. This was necessary when the roadway of Hyde Vale was constructed around 1834 (Henry S. Richardson's "Greenwich: its history, antiquities, improvements and public buildings", written in 1834, refers to "The new cut called Hyde Vale, leading from Royal Hill to Conduit Vale"¹). Conduit Vale was previously named Sot's Hole - and that old moniker had a number of tunnel legends associated with it... true legends as it turns out.

After continuing under Hyde Vale (with the curious muffled swooshing sounds of vehicles passing overhead), the arch returns, giving a ceiling height of five feet or so. A junction appears ahead, along with the sound of running water: to the right, the stumps of two blocked-off branches can be investigated, and to the left the way on is through a deep sump. At this junction the stream of water disappears into the floor down a steeply-sloping pipe, presumably into a deeper "modern" sewer. After a while the passage gets much lower, the fabric of the walls gets older (chalk blockwork in places), and marvellous mineralisation is encountered - stalactites and iron-stained flowstone on both walls and floors. By the end of the journey, the explorer has ascended some 50 feet from the point of origin in the cellar-like structure inside the park.

Above and below: under the upper section of the Hyde Vale roadway; note the chalk blockwork used in the walls to save bricks.


Uphill from the blocked branches, an isolated ancient section (early 1600s judging from the bricks) is located in the back garden of a house. This segment is filled with semi-liquid mud and dips down steeply in the uphill direction - some type of upside-down u-bend silt catch-pit design which has worked well. The downhill end of the segment is bricked up and also broken in from the surface. Removing the mud would be a Herculean task, with all of it having to be carried through the house in buckets over pristine carpets; there is no rear access at all. But if the mud could be removed, a good length of "brand new" old passageway would be revealed - the possibility is intriguing.

Above: the muddy isolated sump - digging (and pumping) could yield exciting new passageway

John Stone covered the Hyde Vale conduit quite well in his 1914 account of subterranean Greenwich; in modern times the late Dick Moy pioneered a full traverse of the passageway in the days when an uninterrupted journey was still possible. Dick kindly gave us the location of the access point in Hyde Vale - it seems to be one of those things that is handed down through the generations without ever being widely known. Should the conduit be opened to the public? Yes and no. The lower section is very safe, and definitely suitable. The much older upper wet section is really the domain of hardened well-equipped cavers, and would give the health and safety fascists in Greenwich Council an opportunity to spout their nonsense.






Above: two of Stone's photos, the upper image showing the view uphill through the sluice; the boards prevent the visitor sinking into 4-5 feet of mud.

What is No.2?


In 1776 (+/- a year) the Royal Hospital carried out a major programme of cleaning and repairing the 13 different conduits that supplied water to it; we know this because it is repeatedly referred to in the extensive 1780 Admiralty survey: "All which Conduit head lead pipe & brick drain were repaired and cleansed at the expense of the Hospital about 4 years ago." The stone disc set into the conduit building at the top of Hyde Vale showing "No.2" is simply for administrative purposes. With so many different heads and receivers, you have to know just which one you're talking about. The numbers start on the west side of the park, finishing with 13 near Maze Hill over to the east.

Here is the full description from 1780:

...a large brick arch, well constructed - Which arch passes from thence, out of the Park, under Croom hill, under the public highways to a hollow or valley, commonly called Sots Hole, or Conduit Vale, where it terminates at another door, and having several perpendicular shafts for air holes, at different distances, in the extent thereof - On the left hand side of the floor of this arch, the leaden pipe of supply above mentioned extends the whole length, and at the S. W. extremity of the said arch, turns suddenly to the left, and lyes in another smaller arch, which extends up the valley of Sots Hole to a Conduit head No.2 near the Horse Pond, on Blackheath, at the end of Chocolate Row; and which arch has one short square turning, and two small branches extending into the rising bank adjoining eastward, all underground.

The leaden branch of supply, in the said Drain, proceeds about half way only, up the valley of sots hole, and terminates at a dam cross the said brick drain, which stops and collects, all the several supplys from the springs in the bowels of the earth, and conducts the same collectively into the mouth of the said pipe.

Conduit water wasn't supposed to be free, although it was frequently intercepted en route - here's a bill (1 pound 5 shillings) for conduit water from the ledgers of the Hospital:


¹ Many thanks to Mike Leader (Governor Archivist, Blackheath Bluecoat School) for pointing this out.

The tunnels of Henry VIII's Placentia

In the main quadrangle of the former Royal Hospital for Seamen, subsequently the Royal Naval College, now part of Greenwich University, stood Henry VIII's Palace of Placentia. There are remains of considerably earlier structures on the site dating back to the 14th century, and the first photo below shows a sewer from that pre-Tudor era revealed during the major excavation carried out by Philip Dixon in 1970-71. The second photo looks along a later sewer of Henrician vintage, originally about 3 feet high but now partially filled with silt. A larger sewer of more recent date (17th century) was also uncovered. The riverside entrances to all the sewers were blocked when a new river wall was built around 1700 for the Royal Hospital. For the subterranean enthusiast, these various tunnels span a wide time period, and present a miniature history of sewer design. Sadly none of them are currently accessible.

Maze Hill Conduit

The only accessible section of this conduit is the entrance chamber, located in the back garden of a house in Maze Hill. The three-foot-high passageway exiting the chamber is bricked up after a foot or two - a small hole drilled through it yielded only earth, suggesting that the tunnel has at least been decapitated and filled, if not robbed out completely. The brickwork of the chamber is in very good condition, possibly having been repaired in the 19th century.

Maze Hill Mine

The title above fails to identify this as either a sand or chalk mine - because we simply don't know. My view is that it is (or was, if it has been quarried away) a chalk mine behind Maze Hill station hard by the roadway of Maze Hill. Per considers it to be a sand mine on the hillside immediately beneath Vanbrugh Castle. For reasons of harmony between friends, I remain impartial on the issue. But the map/elevation, said to date from the 17th century, is unequivocal - there is a pit with entrances to three galleries clearly shown. Westcombe Manor House appears towards the top of the plan (ie East), the foundations of which have subsequently been located in an archaeological dig in the back garden of 66 Foyle Road. If the galleries are still there, then valuable property is inescapably undermined either way, and efforts must be made to locate the passageway. This is fact, not legend.