Henry Gwyn Jeffreys Moseley

Henry, known as Harry to his family, was born on 23^rd November 1887 at Weymouth, Dorsetshire to Henry Nottidge, and Amabel Moseley. His father was a protégé of Charles Darwin and founder of zoology at Oxford University. Both grandfathers were also well renowned scientists.

Educated at Summer Fields School, near Oxford he received a scholarship to Eton where studied under T.C. Porter, one of the first Englishmen to work with x-rays.It was at Eton that Henry first became interested in the structure of the periodic table. In 1906 he entered Trinity College, Oxford, on a scholarship. He did some work in the Balliol-Trinity laboratory, but found Oxford offered little scope for independent work and had a very conservative syllabus lacking content on contemporary developments in physics. As a result he gained only a second class honours in 1910.

The University of Manchester had a reputation for a more lively interest in science and a strong appreciation for its connection to industrial advancement. In 1900 a new physics laboratory been opened by Professor Arthur Schuster. Henry started work as a lecturer and demonstrator there under the guidance of Professor Ernest Rutherford in September 1910, teaching second year students about electricity and helping engineers improve their knowledge of physics. Henry found teaching a frustrating activity commenting: “The students are docile but mostly stupid, and repeating the same thing to 100 different students becomes at times monotonous. There is however the saving grace of intelligence amongst a few. These give more trouble than the rest. They get their experiments finished in one hour, instead of two, and I have to rack my brains to find something to keep them good and quiet for the rest of the time.” He rarely arrived more than a few minutes before he was due to demonstrate and left as soon as the allotted time was up. Of Manchester itself, he often complained to his mother about the terrible weather, in particular the thick fog that tasted acrid and tickled his throat.

Rutherford told Henry to refrain from trying to engage in any research work before December 1910 on the grounds that his teaching staff rarely had time or energy for such matters, but Henry insisted. Rutherford relented and asked him to conduct some radioactivity experiments. At first Henry had to make and set up much of his own equipment for these experiments because the assigned laboratory assistant was pre-occupied repairing Rutherford’s car.

Throughout his life Henry was a reserved, slightly aloof and very seriously minded individual. At seminars he rarely spoke unless a topic he considered a specialty arose and then he would be economic with his words before falling silent. He was quite independent in his work and not averse to contradicting Rutherford when he thought an error had been made and whose tea-time talk and joking he considered inappropriate for a Professor of Physics.

Henry enjoyed the cultural offerings of Manchester, in particular the Halle Orchestra, theatre and cinema. He played bridge and tennis and enjoyed long walks in Derbyshire. He often dined with old family friends and entertained colleagues at his lodgings.

In April 1912, Rutherford offered Henry a share of the John Harling Fellowship for the next academic year. It paid the same as his demonstrator post (£125 a year), but meant all of his time could be devoted to research and experimentation. He would often work for 15 hours straight or into the early hours of the morning. Recently published work by a scientist called Laue, conversations with Niel’s Bohr, a frequent visitor to Rutherford’s lab, and W.L.Bragg’s technique of using diffraction to measure the various x-ray spectra associated with specific elements all influenced the direction of Henry’s research. He asked mathematical physicist C.G. Darwin (grandson of Charles Darwin) to collaborate with him. Henry discovered that the properties of a chemical atom defined its atomic number based on a precise mathematical relationship to its x-ray spectrum, rather than being simply an arbritary number based on atomic weight as perviously thought. This became known as Moseley’s Law. His law made it possible to identify gaps in the periodic table, predict within which series the undiscovered elements would belong and establish that there would be only 15 metallic members. The work was published in July 1913.

In spring 1913 Rutherford offered Henry the full fellowship, but he refused it as he did not believe it a good idea to remain in one place too long. He considered a move to Germany, but concluded that experimental physics there was not as mature as in England. In December 1913 he opted to move to Oxford to live with his mother and to work as an independent researcher at Townsend’s laboratory.

When war was declared in 1914 Henry had just arrived in Australia. He fulfilled his obligation to speak at a conference and, through a strong sense of duty, returned to England as quickly as possible with the intention of joining the Royal Engineers. After a struggling to be accepted he was commissioned and sent to Aldershot for training in October 1914. He soon became responsible for the 13^th Signals Company, 38^th Brigade, 13^th Division, was sent to Alexandra in June 1915 and moved to Gallipoli in early July. In letters home he outlined his military duties, but also described the birds and flowers of his new environment, a pleasant distraction from the war.

On the night of the 6^th/7^th August,38^th Brigade was detailed to take part in an attack at Chanuk Bair. It was during this prolonged action that he was killed by a shot to the head while sending an order by telephone on 10^th August 1915. Death was instantaneous.

‘Sacrifice of a Genius’, ‘Too Valuable to Die’ and ‘A Brilliant Physicist’ were some of the headlines that relayed the news of Henry’s death to the public and scientific community. In a June 1914 reference letter Rutherford had stated: “Mr Moseley is one of the best research students I ever had. From the first he showed unusual originality and capacity as an investigator. He has published a number of papers which have contributed materially to our knowledge”. Rutherford had tried unsuccessfully to get Henry moved to war time research and in a letter to Nature after his death expressed great frustration that the usefulness of scientific men in non-combatant roles had not been appreciated by the authorities.

There was much speculation that Henry would have been awarded a Nobel Prize had he lived and records show that he was nominated. Perhaps significantly, no Physics Prize was awarded in 1916. A scholarship at the Royal Society was founded through his Will, the first recipient being H.R. Robinson, a former Manchester colleague. At the University of Manchester, a Moseley Memorial Prize in Physics was established and is still awarded each year. A plaque was also erected at the University in his memory.

For detailed information about Moseley’s science and the papers he wrote please consult the sources listed below.