North Wall Doorway

Moving Easterly along the North wall there was a clear gap that we assumed was a doorway - so we started digging...

There is a good deal of lead slag a few roof tiles, both clay and stone, loads of brick and lots of mortar. The stuff here is much more like building rubble than the other places we've excavated so far.

Anyway, this is what we found....

The door step is substantial; 4 feet wide and chunky! It's well worn being smooth and rounded on the outside and inside edges. It was quite a feeling standing there thinking that probably no one has stood there for 200 years and 250 years ago Joseph Whitfield would have been regularly crossing the threshold during his daily visits to the mill.

Finds from the North West corner of the first room.

While we found loads of stuff within the first room, during the excavation on the outside NW corner we found almost nothing, except, there was masses of lead slag.

This area was really difficult to interpret what was happening; the end (W) wall of the first room was clearly an afterthought. It was badly built and was not linked in to the North wall, so we thought the Noth wall would just carry on in a Westerly direction. It did for about 300mm then stopped.

One thing we did find which was of interest was a big chunk of metal....

As yet we have no idea what it is.

The Hole in the North Wall

In the bank on the North West side of the ruins is visible a wall with a hole in. Clearly this is not just some random hole caused by stones falling out as it is quite regular and has a lintel above it. Our plan was to dig into the hole and also chase the wall left as far as we could. The success was limited; we had to abandon digging out the hole as we feared it may become unstable and there's a massive ash tree in the way. Also the wall pretty much stopped after a few feet. In fact it probably did go further and has collapsed.

 

So, what we did next was to move about 3 metres left and started a trench into the bank hoping to pick up the wall further round (to the South).

Unfortunately this proved to be a waste of time. What we did discover (we think) is that on top of the natural clay there is a grey layer of "stuff" which we think will be some sort of spoil from the industrial process. It contains brick fragments, coal and bits of pink sandstone. On top of this layer is more clay and broken sandstone which we think was probably tipped there when the big pond was excavated. (on the East side of the ruins)

About another 3 metres left (South) of this trench Sarah started scratching about around some stones that looked like they could be a wall. Before long she had found that it was indeed a wall and she started chasing it right (North)

It soon became clear that her wall was heading for my trench and so I started digging down to where it would intercept. This next picture shows what we found....

These 4 stones were perfectly in line and were all pink, showing that they had all been heated to high temperature. The following picture gives a better idea of where they sit in the overall context of the wall.

We have now stopped excavating this area and are awaiting the visit of Lynn Willies who will hopefully be able to make some sense of what is happening here.

Finds in the First Room

The picture below shows the type of layers in the first room. The top layer was ivy and topsoil, next there was rougher soil and smaller stones; this layer contained most of the finds, then there was a layer of very sandy, yellowy grit. In all layers there were BIG stones which clearly had collapsed from the walls. Finally, mainly in the East side there was a layer of compacted coal dust which we have pretty much left in full. There was some on the West side (not as much) but we wanted to get down to the floor level so we removed it.

We were quite surprised at the lack of roofing material that we found; we can only assume it had been robbed for use elsewhere.

So, finds in the first room were:

1. A chamber pot.
2. A casserole pot.
3. A jug. (diameters: base 110mm, widest point 150mm, top 110mm. Height 195mm)
4. A plate. (230mm diameter)
5. Roof tile. (330mm long rounded on the end that has the lug on the rough side)
6. General bits of pottery.
7. Assorted glass.
8. Bones.
9. Pottery - not sure what this is.
10. Part of a big bowl used to make dough. (this was in the lowest layer)
11. Lead slag.
12. Metal.
13. A big chunk of metal taken from the gap in the middle of the floor.
14. Bricks (one of which came from the very bottom).
15. Pink stones.
16. Stone roof slates.
17. Stone ridge tiles?
18. Shaped stones.
19. A button back. (17mm dia)
20. A strip of lead.
21. A Key.
22. Stuff that didn't feel like it was natural to the area - possibly ore/flux/some waste product from the process.

Picture 1. A chamber pot.

Picture 2. A casserole pot.

Picture 3. A jug. (diameters: base 110mm, widest point 150mm, top 110mm. Height 195mm)

Picture 4. A plate. (230mm diameter)

Picture 5. Roof tile. (330mm long rounded on the end that has the lug on the rough side)

Picture 6. General bits of pottery.

Picture 7. Assorted glass.

Picture 8. Bones.

Picture 9. Pottery - not sure what this is.

Picture 10. Part of a big bowl used to make dough. (this was in the lowest layer)

Picture 11.  Lead slag.

Picture 12. Metal.

Picture 13. A big chunk of metal taken from the gap in the middle of the floor. (Image of cleaned up find to follow.) And here it is.

Picture 14. Bricks (one of which came from the very bottom). The dimension of the full brick is 235mm x 60mm x 115mm. The others look to be similar although it's difficult to tell with the darker bricks in the top picture as they are quite distorted, presumably by intense heat, I assume they were used in the cupola.

Picture 15. Pink stones. There are considerably more than shown here, I just couldn't be bothered to wash them all! I read somewhere that the pinkness is due to exposure to extreme heat.

Picture 16. Stone roof slates.

Picture 17. Stone ridge tiles?

Picture 18. Shaped stones. We have no idea what this was for, I assume the only reason we found this one is because it is broken.

Picture 19. A button back. (17mm dia)

Picture 20. A strip of lead.

Picture 21. A Key.

Picture 22. Stuff that didn't feel like it was natural to the area - possibly ore/flux/some waste product from the process.

Inside First Room

Having excavated as much as we wanted in the first room (the furthest West) there are a few questions which we can't answer.....

1. Why is the North wall stepped out at the bottom yet the West wall isn't?
2. Why is there a big gap in the middle of the floor?
3. On the North wall there's 1 stone that protrudes and on the top face has been chiselled out so there is a recess - why?
4. Lots of coal dust on the floor - what was it used for?
5. The East side of the room has a nice stone flagged floor but the other side of the "gap" it's rough, why?
6. Are there signs of burning on the West wall half way up?

Only 15 years?

I just found this....

here

No longer a reverberating cupola.

I just found this.......

here.......

Rope Works

Just found this....

It comes from.....

showing that by 1817 Bower's Mill was a rope works.

Research at Sheffield Archives

Having searched for Bower's mill on the www we found references in the National Archives http://www.nationalarchives.gov.uk/a2a/records.aspx?cat=199-md37073708&cid=0#0

The records in question were held at Sheffield - handy!

We visited on 6th Feb 2012 ad this is some of what we found:

And below is our "translation":

Bower's Mill 6th, August 1744,

Gentlemen,
                   The Secretarys of the 2nd, Instant I have, Shall observe to pay no
more money for pretended Debts as owing by Geo: Clarke for the Companys
Account 'till I have your orders,       I have paid James Potter no money 'tho he
had demanded sundry times, believing he Charged more than due,    will take an
Account this week of all hitherto Claimed & Send it you, . . . . . . . _________
          4th Instant at Bakewell Draw on Secretary Farrington for £111 .  .
Excise money payable to yo, Commiss rs, 28 days after date, ___ as the Excise
this time runs so Low shall be Short of Cash & desires to know if you permit
me to draw upon you for what more I Shall have Occasion to pay for Bought Ore etc a,
          As many of yo, Miners cannot Support their Familys for a Quarter without
borrowing Money and their Ore not being dressed up I know not how to lend them
Safely, thinks it best to dress up & measure yo, Ore twice each Quarter I then can
know what money to advance them As was always done in Jethro Normans time
      I believe in so doing we Shall raise Considerably more Ore, Consequently may
lower yo, price of Cope, __________ Annex'd you have yo, Lead Account to 24th, June
 which hopes you'll find right. . . . . . . I am Your Obed t, Serv t,
                                                                      Joseph Whitfield
P.S. I am just informed Geo, Clarkes wife
sets out tomorrow morning by y, Derby
wagon for London, having heard by a
letter from Widdow Holden to Geo: Clarke
junior that her husband was Imprisoned?
                               Idem          W:____

We assume this is a letter to the shareholders of the London Lead Company.
yo, = your
We're not sure of the term "Cope" (2nd last line) - Coke or Coal would make sense but the word really does look like Cope..........
The word IS in fact cope and relates to the term "lot and cope" which is some sort of duty that we don't fully understand.
            

The Reverberating Cupola

Cupola smelting

The mills which had superseded the ancient bolehills in the late 16th century, a development described above in section 3, were themselves superseded in the 18th century by the gradual introduction of a new type of furnace known as the cupola.^[37]

The old mills had a number of disadvantages. Their characteristic overheating and dissemination of polluting fumes made it necessary to close the smelter down at the end of each day’s work. The hearth burned out quickly and regular weekly repairs or rebuilding were necessary – between 24 June and 29 September 1657, for instance, thirteen new hearths were required at the Upper Mill in Wirksworth^[38] Water-powered smelting mills were restricted to riverside sites and “white coal” fuel required a good supply of timber. By the 18th century timber supplies were running out and, where coke or coal was used because of timber shortages, impurities, particularly sulphur, were introduced into the lead. It was, finally, less efficient than the cupola.

The cupola was a reverberatory furnace. The fuel was burned in a combustion chamber at the side of the furnace, separate from the “charge” of ore, thus avoiding any contamination. This removed the disadvantage in using coal, which was far more plentiful than timber. The ore was loaded from a hopper into a concave furnace with a low, arched roof and a tall chimney or a flue at the opposite end from the combustion chamber. The flames and heated gases from the fuel were drawn across the charge by the draught from the chimney and beaten down by reverberation from the low roof. Slag on the surface of the molten lead was raked off and the lead itself poured into an iron pot at the side, before being ladled into moulds.

Several factors contributed to the cupola’s greater efficiency than the smelting mill. Unlike the smelting mill, the cupola could be operated continuously. Since the air flow over the ore was less powerful than that from the bellows of the blast furnace fewer lead particles were blown away. Further lead was saved by the fact that since the fuel and the charge were separate none of the lead was lost into the ash. Since no water power was needed the cupola had a fourth theoretical advantage of being freed from the riverside location of the blast furnace, and able to be placed in the most convenient site for supply of ore and coal. However the higher temperatures needed to melt the slag recovered from the primary melt required a water powered furnace and, since slag mills tended to be placed next to the cupolas, most cupolas remained in riverside sites.

Many cupolas had long horizontal flues, which were introduced to trap pollutants before they could be discharged into the air. Since the pollutants included metal vapour, the sweepings of the flue could also be recovered for re-smelting.

http://en.wikipedia.org/wiki/Derbyshire_lead_mining_history

Reading Resourses

http://www.pdmhs.com/PDFs/ScannedBulletinArticles/Bulletin%2011-1%20-%20Derbyshire%20Lead%20Smelting%20in%20the%20Eighteenth%20.pdf

http://www.pdmhs.com/PDFs/ScannedBulletinArticles/Bulletin%2012-4%20-%20An%20Eighteenth%20Century%20Red%20Lead%20Production%20Record.pdf

http://books.google.co.uk/books?id=7kwDJclq3jgC&pg=PA197&lpg=PA197&dq=%22bowers+mill%22+-halifax+ashover&source=bl&ots=qVlDBtSwAa&sig=yaGZ7HjXpx087w22X2EzrlsDNfU&hl=en&sa=X&ei=XictT43BO8HX0QXj9LSsCA&ved=0CDMQ6AEwAg#v=onepage&q=%22bowers%20mill%22%20-halifax%20ashover&f=false page 197

http://willsdb.gukutils.org.uk/DBY/WillsO.html 1774

http://www.sheffieldhistory.co.uk/forums/index.php?/topic/7151-road-development-in-south-yorkshire-and-north-derbyshire-1700-1850/

What Bower's Mill was for.

Lead Smelting

---

Early methods of separating the lead from the waste products were primitive. Smelting took place on hilltops facing into the prevailing westerly winds which provided the draught for the fire. It involved building what was essentially a large bonfire on top of the hill, using alternating layers of wood and ore. It worked because lead has a relatively low melting point but it was very inefficient and used large quantities of wood.

Smelting usually took place in the spring when several days of strong wind could be relied upon. Ore and fuel was stockpiled and the process would last until the wind died down or the supplies of timber and ore were exhausted. As the lead melted, it was collected at the base of the fire and channelled into moulds called pigs.

These hilltop hearths were known as boles and their sites live on in the place-name Bole Hill. There is a hamlet named Bolehill between Cromford and Wirksworth. Boles had become obsolete by the end of the 16th century because of a new technological development, the ore hearth.

The ore hearth was similar to a blacksmith’s forge but here the draught was provided by bellows powered by a waterwheel. The smelting sites therefore transferred from the hilltops to the river valleys. These hearths were much more efficient. (They were about 55% efficient.) In fact it became economic to reprocess the slag which had been produced by the boles, and recover more lead as well as smelting new ore.

Hearths still relied on wood as fuel, but it was now specially prepared for the purpose and was known as white coal. The timber was chopped up into small chips and dried over a fire before use. White coal was produced in woodlands which were specially managed for the purpose.

This method of smelting required the mixture to be constantly stirred by the smelters, who consequently worked in an atmosphere of poisonous fumes. A man employed as a lead smelter usually had a relatively short life.

The final technological development was the cupola or reverberatory furnace. This used coal as fuel and was completely enclosed. The fire and the ore were separated by a low wall and the flames and heat were ‘reverberated’ on to the ore from the domed roof. The reverberatory furnace was first introduced into Derbyshire by the London Lead Company in the mid 1730’s at Bower’s Mill, Ashover. The furnace used a tall chimney to provide the draught for the fire. These smelters were often situated on the barren moorland where there was less chance of farm animals being poisoned by the fumes. They were much more efficient than the ore hearth, about 65%.


Thanks to Peakland Heritage website for this article