Glacial Boulder Trail 2 – The Louis Barrow Trail
Around Bournville and Cotteridge Park

Louis Barrow, the Bournville Boulders and the Bournville Works Magazine


The boulders encountered on Trail 2 played an important part in the early 20th century history and interpretation of Birmingham’s erratic boulders and their glacial origins. This trail therefore invites some additional information beyond the scope of the accompanying leaflet. Boulder discoveries made around the Cadbury factory in Bournville and in Cotteridge Park were meticulously recorded in the Bournville Works Magazine (BWM) thanks to the interest of the chief engineer, Louis Barrow. Several articles and correspondence in the BWM give an insight into the state of the infant science of glaciology at the time. The Bournville boulder story is embedded in the history of the Cadbury family and the Bournville chocolate factory. Illustrations from the Bournville Works Magazines are reproduced here courtesy of the Cadbury Archive, Mondelēz International. Quotations are numbered and referenced at the end.

The Cadburys and the origins of Bournville

The story begins in 1824 with John Cadbury who ran a small business in the centre of Birmingham where he sold tea, coffee and drinking chocolate.  He was a devout Quaker and an advocate of the temperance movement, and promoted these drinks as healthy alternatives to the evils of excessive consumption of alcohol. In particular he saw the potential of cocoa and he opened a factory to develop new ways of turning cocoa into a more palatable drink. With his brother Benjamin on board the company thrived as Cadbury Brothers. Control of the expanding business passed on to John’s sons, Richard and George in 1861, and the company’s fame grew with the development of the popular Dairy Milk chocolate bar.

Following the philanthropic Quaker principles  of their father, George and Richard decided to move  their thriving chocolate business from the city centre to the outskirts Birmingham.  They wanted to create working conditions and homes for their workers which would lift them out of the squalor of city dwelling. A large site was found close to the canal and railway network, with Bourn Brook running through it as a source of water (fig. 1). The new factory was opened in 1879 with plenty of space for housing, and Bournville was born. At the turn of the 20th century the Bournville Village Trust was set up to manage and develop the estate in accordance with its founding principles, as it does to this day. Louis Barrow was appointed as chief engineer in 1900, and the BWM was established in 1902.  This magazine flourished for over 60 years, providing an insight into the world of the Bournville Works during that period.

Bournbrook Plan
Fig. 1: Auction notice for the sale of the Bournbrook site, 1878
Louis Barrow

Louis Barrow (fig. 2) was born in Kings Norton in 1865, and was connected to the Cadbury family through John Cadbury’s marriage to Candia Barrow. He spent many years as a student at Mason College (the forerunner of the University of Birmingham) and his studies included the subject of geology under the guidance of Professor Charles Lapworth (see Glacial Boulder Trail 1 for more on Lapworth). After an apprenticeship at the Tangye Brothers engineering works in Soho, Barrow moved on to the development and manufacture of bicycles. Back at Tangye’s, he progressed to the position of head draughtsman before becoming chief engineer at the Bournville works at a time of expansion for the factory and the surrounding Bournville village.

Over the years excavations around the Bournville works and Cotteridge Park unearthed numerous glacial erratic boulders. Barrow’s interest in the subject inspired him to consult his former teacher, Charles Lapworth. A lively correspondence ensued, and we are fortunate that this archive has survived, mainly in the Bournville Works Magazines with several articles on erratic boulders and their place in the geological story of the Ice Age.

Louis Barrow
Fig. 2: Louis Barrow. Image from ‘A Century of Progress 1831-1931’, Cadbury, Bournville, March 1931
Barrow’s enthusiasm extended to the later excavations in Cotteridge Park, where he was instrumental in preserving the boulders with an explanatory map. His reasoning for this interpretation reflects the same philanthropic ethos which inspired the Cadburys: “He was prompted to present the map by the thought that the mere collection of boulders possessed little interest for the lay mind unless some explanation of their probable history was given”.1 It is thanks to Louis Barrow that most of the erratic boulders on this trail have survived, and hence the dedication of Trail 2 to his memory.


The Bournville Works Magazine

The Bournville Works Magazine archive provides an extraordinary window into the bygone world of conditions for the workers at the Cadbury factory in the first half of the 20th century. It includes reports on a vast range of activities including needlework, lace making, photography, sporting activities, and following its opening in 1927, the performances which took place in the Bournville Concert Hall. From Louis Barrow, there are the erratic boulder discussions outlined below, but in addition he wrote a detailed and well-illustrated 2 part article on the Iguanadon, a dinosaur of the Cretaceous period. It seems that Barrow had found some fossil bones on the Isle of Wight which stimulated a particular interest in this subject, and inspired him to write this item. It contains some historic photos of the Iguanadon model which was created for Richard Owen’s Crystal Palace dinosaur display for the Great Exbibition in 1851.2

Fig. 3: Cannon Hill Park Boulder, photo by A.E. Harris

Fig. 3: Cannon Hill Park Boulder, photo by A.E. Harris

The main period of writing in the BWM on the subject of glacial boulders is from 1910 – 1913, with a few items of interest before and after these dates. Starting in January 1906, there is a short letter describing a boulder found at the Bournville brickyard and placed beside the door of a private house. Though this boulder is now lost, the editor’s comment is worthy of note: “One of the largest glacier deposited rocks in the locality is that at Cannon Hill Park… The boulder is of the same formation as the picturesque Arenig group of mountains, near Bala Lake”.3 A boulder in Cannon Hill Park that is still on display was discovered during excavation of the ornamental lake prior to the park’s opening in 1873. This editorial note suggests that it had become a well-known item of interest. In the pages of these magazines and elsewhere it is frequently used as a reference for comparison with other erratic finds. (The Cannon Hill Park boulder will be the starting point for Glacial Boulder Trail 7, a cycling Trail around south Birmingham.) A photo of this boulder with an interpretation board appears in the April 1908 issue of the BWM (fig. 3). The final part of the magazine caption states: “In all probability it comes from the mountains of Wales, and was dropped by an iceberg while floating over the midland sea at the period when Great Britain was an archipelago of ice-clad islands”.4 This theory was soon to be superseded by the evidence-based interpretation that the erratics were carried by glaciers over land, but this caption shows that earlier interpretations were still accepted. The description on the board is sadly illegible.

The Bournville Boulder by Professor Lapworth F.R.S.’ BWM February 1910

The first significant item on the subject of erratics in the BWM is an article by Professor Charles Lapworth in February 1910 entitled ‘The Bournville Boulder’ (fig. 4). Here we learn about a boulder found in the factory grounds in 1908 and its intended location in the Girls’ Recreation Ground (Locality 8). (Locality numbers refer to the Trail 2 leaflet.) This was the original ‘Bournville Boulder’. We also learn of a debate between Lapworth and Barrow about the origins of the boulder – was it found in the usual glacial till deposits, or in the much older (Triassic) marl deposits below? It seems that it had been found more than half embedded in the marl, and Louis Barrow believed that this showed that its existence pre-dated the Ice Age. Through analysis of samples and a visit to the site of the boulder’s discovery, Lapworth concluded that the boulder was made of the usual Arenig ash, and its connection with the marl could be explained by the boulder’s location at the bottom of the till, with pressure from above forcing it into the marl. He even suggested a suitable inscription to go on display with the boulder, though there is no evidence that this was ever used: “BOULDER OF VOLCANIC ASH, excavated at Bournville, December 1908; probably brought by ice during the Glacial Period from the Arenig Mountains of North Wales“.5

Fig. 4: The Bournville Boulder, Feb. 1910.
Fig. 4: The Bournville Boulder, Feb. 1910. Five shilling piece (38mm diameter)
for scale (top left)

George Cadbury himself took an interest in the erratic boulder discoveries, and asked Lapworth to write something for the BWM on the general subject of the Ice Age. Lapworth obliged with a detailed article which follows ‘The Bournville Boulder’ in the February 1910 issue of the BWM. In this, Lapworth’s discussion of the Ice Age refers to the work done in the Alps which led to the modern understanding of the formation of ice sheets and the movement of glaciers. Interestingly, he illustrates his article with the same image of the Cannon Hill Park boulder used in the April 1908 issue. He concludes his article with a final reference to the Bournville Boulder and its significance in the wider context of understanding the sequence of events during the Ice Age: “It is well worthy of preservation as a memorial of the Great Ice Age, and as a permanent geological index of the direction of movement of the ice which crossed this part of the Midlands during the Glacial Period”.5 He would surely have been pleased to know that it is still in the same place, (now Cadbury Park) and that new interpretation and outreach is underway in 2022 (fig. 5).

Fig. 5: The Bournville Boulder in the Girls' Recreation Ground, BWM October 1911
Fig. 5: The Bournville Boulder in the Girls’ Recreation Ground, BWM October 1911
The Erratic Boulder! by A.C. Hunt’. BWM July 1910

In this article from the July 1910 issue of the BWM, A.C. Hunt seems to be intent on fuelling the alleged ‘dispute’ between Barrow and Lapworth about the original location of the erratics: Triassic marl or glacial till. The new context was the unearthing of another large boulder “recently placed on the southern bank of Bournville Lane”6 (Locality 1a). It was found during widening of Bournville Lane, apparently within the blue marl, and Lapworth was invited to see the boulder ‘in situ’, to ‘prove’ Barrow’s theory. Barrow’s letter to Lapworth survives at the Lapworth Museum, complete with diagrams and Lapworth’s annotations after seeing the boulder (figs. 6a & 6b).

Fig. 6a: Louis Barrow's letter to Lapworth 23/5/1910 page 1
Fig. 6a: Louis Barrow’s letter to Lapworth 23/5/1910 page 1 (courtesy of the Lapworth Museum of Geology)
Fig. 6b: Louis Barrow's letter to Lapworth 23/5/1910 page 2
Fig. 6b: Louis Barrow’s letter to Lapworth 23/5/1910 page 2 (courtesy of the Lapworth Museum of Geology)
Fig. 7: Boulder now at Locality 1a, in its position as re-discovered in May 1910
Fig. 7: Boulder now at Locality 1a, in its position as re-discovered in May 1910
In fact, Lapworth realised immediately that it had been placed there when he unearthed a brick. Though the ‘dispute’ may now seem like a storm in a teacup, this episode reveals some interesting facts. A long-standing Cadbury employee called Mr Brice remembered that the boulder had been found around 20 years earlier during a previous road-widening episode, and that Richard Cadbury had wanted to take it to Uffculme, his home in Queensbridge Road, Moseley. The operation was deemed too difficult at the time, so the boulder was moved into a trench and re-buried. This shows that there were note-worthy glacial boulder discoveries before Louis Barrow’s appointment, but there was not sufficient interest at the time to ensure their exposure and preservation. The article also provides us with a valuable photo showing the boulder in its re-discovered position, (fig. 7) and there is a comparison with the Cannon Hill Park boulder in Hunt’s summary: “…its weight is about three tons, and rather smaller than the one in Cannon Hill Park”.6
‘The Bournville Glacial Boulders by Louis Barrow’. BWM December 1910

In December 1910, Louis Barrow wrote a long article expanding on his theory about the origins of the boulders, along with an interesting exposition on the underground water systems around the Bournville works. Of particular interest for the erratic story is his description and photo of a large boulder (fig. 8), found during the Bournville Lane road works, with a caption identifying it as the boulder at Locality 1b. The caption also makes further reference to the Cannon Hill Park boulder: “Its weight is estimated at over 5 tons, and it is larger than the Arenig boulder in Cannon Hill Park”. 7

Fig. 8: Large boulder now at Locality 1b as discovered near Bournville Station in 1910
Fig. 8: Large boulder now at Locality 1b as discovered
near Bournville Station in 1910
Fig. 9: Louis Barrow's boulder location diagram and index
Fig. 9: Louis Barrow’s boulder location diagram and index
‘The Bournville Boulders’. BWM June 1912

By 1912, there is a change of focus to Cotteridge Park where work was underway to level large areas at the northern end of the park. An item in the June 1912 issue refers to the boulders found during these excavations, and the painstaking work done by Louis Barrow to record their locations and have them mounted with suitable interpretation (Localities 5a-e). Barrow’s location diagram and index (fig. 9) shows the original and moved locations of many of the Bournville and Cotteridge park boulders. This has proved to be a valuable resource in discovering how many boulders have survived to the present day. By the time of this BWM article, an array of the largest boulders was on display at the higher southern end of the park, as shown in the photo (fig. 10). The fame of the boulders had spread beyond Bournville, and there were field visits from the Birmingham Natural History and Philosophical Society in March 1912 and from the Worcester Naturalists’ Club in May. On each occasion the visitors were accompanied by Louis Barrow, and each time they were entertained to refreshments by the Firm.

Fig. 10: Array of glacial erratic boulders in Cotteridge Park, 1912
Fig. 10: Array of glacial erratic boulders in Cotteridge Park, 1912
Fig. 11: The Cotteridge Park indicator map showing the extent of the ice cover
Fig. 11: The Cotteridge Park indicator map showing the extent of the ice cover
‘The Bournville Boulders – Cotswold Geologists at Bournville’. BWM August and September 1913

By the time of a visit from the Cotswold Naturalists’ Club in 1913, the indicator map showing the extent of the ice cover (mentioned earlier) had been installed beside the main array of boulders in the park at Locality 5 (figs. 11 and 12). We learn from this report that “the visitors examined the indicator which has been presented by Mr. Louis Barrow, and which consists of a glazed map set upon a stone pedestal. The map, which was prepared by Mr. Louis Barrow and drawn by Mr. A. Matthews, is based upon information supplied by Professor Lapworth, Mr. Jukes Brown, and members of the Birmingham Natural History and Philosophical Society, shows the British Isles during the glacial period, and indicates by means of lines the probable course of the glacial boulders”.1 The map and most of the pedestal disappeared long ago, but the dilapidated base survived until 1918 when it was removed and replaced with an information plaque set into the ground. We are fortunate that this facsimile of the original map has survived.

The Cotswold visitors were shown round by Louis Barrow and Professor Lapworth. Barrow gave an address about the boulders which indicates that he had by now conceded to the prevailing theory of their origins: “That they have been carried here by ice is proved by the striations on the boulders (seen clearly on the large boulder near Bournville station) …and by the presence of boulder clay”.1 Barrow mentions: a “big saucer-shaped boulder blackened by smoke and coal dust discovered on the site of the Bournville Midland Railway sheds”.1 The array of boulders at Locality 5 were cleaned and restored during the restoration project in 2018, but there is one likely candidate amongst the surviving boulders which answers this description – apart from the coal dust! In his address Barrow describes a “rough boulder near Bournville Station” which is almost certainly boulder 1a in Trail 2. He leaves us with the intriguing statement: “In the concrete foundation under this boulder have been deposited certain records in an air-tight case, which may prove of use in the distant future”.1

Fig. 12: Cotteridge Park boulders with the map and pedestal, 1913
Fig. 12: Cotteridge Park boulders
with the map and pedestal, 1913
The Cotswold visit concluded with a long address by Lapworth: ‘The Midlands and the Great Ice Age’ eloquently summarising the current state of knowledge about the Ice Age with special reference to the Midlands and Birmingham in particular. This was published in the September 1913 issue of the BWM. The Cotswold visit marked the highest point in the early history of the Bournville erratic boulders, and Lapworth’s address was, fittingly, the final word on the subject before the First World War – but there was a little more to come, 10 years later…
Fig. 13: Large erratic boulder found on Rowheath in 1923, now missing
Fig. 13: Large erratic boulder found on Rowheath in 1923,
now missing
‘Another Bournville Boulder’ BWM April 1923

After the war, land was acquired on Rowheath for new playing fields. During excavations a huge boulder was found and photographed (fig. 13), and immediately assumed to be one of the same Arenig boulders found previously in Bournville and Cotteridge Park. We learn from the short item in the BWM in April 1923, that “The measurements are 8 ft. 6 in. long, by 5 ft. wide, and about 3 ft. thick”.8 We also learn that its greatest length lies roughly north-south. Research so far has drawn a blank on what happened to this splendid erratic. We hope that the publicity engendered by the current project may throw some light on its story and better still, can we find it?

Julie Schroder


1. Bournville Works Magazine, August 1913

2. BWM, January and February 1912

3. BWM, January 1906

4. BWM, April 1908

5. BWM, February 1910

6. BWM, July 1910

7. BWM, December 1910

8. BWM, April 1923

The Bournville Works Magazine archive can be viewed by arrangement at:

Bournville Village Trust:

Selly Manor Museum: