Sarah Baines, Associate Curator at the Museum of Science and Industry, on the simple wooden balls that helped John Dalton develop his atomic theory
John Dalton (1766 – 1844) one of Manchester’s most talented scientists and original thinkers, was a member and later President of the Manchester Literary and Philosophical Society, the first and oldest in the world.
After his death some of his personal collection of scientific models and papers remained in the city, at the Manchester Literary and Philosophical Society’s George Street headquarters, like this simple wooden model, made for him by his engineer friend Peter Ewart in Manchester in about 1810, to model the incredibly tiny atomic scale and to demonstrate his atomic theory.
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The model is part of the Museum of Science and Industry collection, and one of the most precious objects we hold. It helps us to understand how Manchester scientist John Dalton first developed his ideas about the three-dimensional structure of atoms.
It is made up of five wooden balls, three with a diameter of 29mm, and two with a diameter of 19mm. Three are joined together, and two are loose. They were probably part of a larger group of wooden balls, and could be fitted together in different shapes to represent different chemical compounds.
They are unpainted, and the grain of the wood is visible. If we examine the model closely, we can see detailed markings. We are not sure if they denote the type of atoms the balls represent, or if they are marks left behind from the process by which Peter Ewart made the model for Dalton.
Dalton was a lifelong Quaker, and was famous for his modest lifestyle. For this reason, some of his possessions were given to the Society of Friends by the family of Isabella Benson – her and her sister Hannah were Dalton’s nearest relatives at the time of his death.
They were kept in Dalton Hall, a Manchester hall of residence founded by the Society of Friends in 1876. Unfortunately many of his artefacts and papers were destroyed on Christmas Eve 1940 in a Second World War bombing raid. Fortunately, some items survived, and the Science Museum had made facsimiles in 1925 (like the one below) of several of the most significant drawings.
In 1957, the University of Manchester took over management of Dalton Hall and the items needed a new home. Some items remained at Dalton Hall, and a few items were given to the Science Museum in 1949, including another atomic model (museum number 1949-21).
The majority of the items were gifted in 1958 by the Society of Friends to the Manchester Literary and Philosophical Society. We think that our wooden model was part of this group of objects. Ownership of the model was transferred to the Museum of Science and Industry by the Manchester Literary and Philosophical Society in 1997.
Dalton created symbols to represent the different types of atoms, and used them to draw diagrams to represent how he thought atoms were arranged. Although the details of his diagrams were not always correct, the innovative principle of diagrammatically representing atomic structure has stood the test of time.
In the Wonder Materials exhibition at Museum of Science and Industry, we look at some of the different ways people imagined the nano-scale long before technology made it possible for us to ‘see’ atoms and how they fit together. It is clear to see the role that human imagination has played in visualising the invisible.
Using his imagination, and his new theory that all atoms of a particular element are identical to each other and different from the atoms of other elements, Dalton tried to think of a way to represent atoms spatially. Dalton was a teacher by nature – he spent much of his career teaching others (including another famous Manchester scientist, James Joule), and he wanted a way to physically demonstrate his ideas to his peers and students. He was the first person to use ball-and-stick models to represent the structure of molecules. We know when and why Dalton had these models made because he describes their production and use in a letter written in 1842, two years before his death:
My friend Mr Ewart, at my suggestion, made me a number of equal balls, about an inch in diameter, about 30 years ago; they have been in use ever since, I occasionally showing them to my pupils… I had no idea at the time that the atoms were all of a bulk, but for the sake of illustration I had them made alike.
Dalton, quoted in Henry, 1854: 124
Atomic models are a tool for communicating theories and ideas, and are often used in teaching. Historian Frank Greenaway muses on Dalton’s legacy: ‘Contemporary critics doubted Dalton’s atomic theory. Dalton’s view of the importance of thinking structurally and three-dimensionally about atoms was in fact far beyond his critics’ perceptions, and his ideas became fundamental to modern chemistry. Writing in the 1960s, W. V. Farrar said that ‘if more chemists had been playing with balls and sticks in the same way as Dalton, the world would not have had to wait so long for the theory of structure’.
The Wonder Materials exhibition is an opportunity for visitors to see his wooden atomic model from 1810 alongside objects relating to the contemporary science story of the isolation of new material graphene in Manchester in 2004.
Sarah Baines is the Associate Curator at the Museum of Science and Industry. She is part of the Collections team, and works on developing the Museum’s science and industry collection. A version of this article first appeared on the Museum of Science and Industry blog.
Wonder Materials is at the Museum of Science and Industry until June 25 2017. The exhibition tours internationally until 2021.
Museum of Science and Industry
Manchester, Greater Manchester
Uncover Manchester's industrial past and learn about the fascinating stories of the people who contributed to the history and science of a city that helped shape the modern world. Located on the site of the world's oldest surviving passenger railway station and only minutes from Manchester's City Centre, the Museum's…