William Cantelo William Cantelo ( born c . 1838 ) was a 19th - century British inventor . Credited with developing an early machine gun , he disappeared from his home in Southampton in the 1880s . While trying to find Cantelo , his two sons saw a photograph of Hiram Maxim , creator of the Maxim gun ; his similarity to their father led them to believe that he had re - emerged under a new name . Background . Cantelo was born around 1838 in the Isle of Wight . He was an engineer who , in the 1870s , owned a shop on French Street in Southampton and a yard in Northam , employing up to 40 people . He was also the landlord of the Old Tower Inn at the end of Bargate Street which derived its name from the Arundel Tower against which it was built . Beneath the pub was a tunnel where Cantelo spent much his time , turning it into an underground workshop . Cantelo was married with three children – a daughter and two sons . He was a keen musician and the bandmaster of the old 2nd Hampshires . Invention . The development of new , rapid - firing guns was becoming a hotly contested area for inventors . The military of countries across the world were looking to secure the most powerful weapons and there was great potential for an inventor to secure a highly profitable government contract . Machine guns were first used during the American Civil War and the Gatling gun , Nordenfelt gun , and Gardner gun had all started gaining popularity . Cantelo wanted to contribute to the revolution . Cantelo used the tunnel underneath the Old Tower Inn for his experiments , and was later joined by his two sons , both engineers themselves . Locals reported hearing noises coming from the vicinity but the family kept their work a closely guarded secret . In the early 1880s Cantelo announced the gun ' s completion to his family . Disappearance . Accounts differ regarding the nature of Cantelo ' s disappearance . Some reports say that he went for an extended holiday as a reward for his hard work , or might have gone off to sell his finished invention . It is also claimed that a large sum of Cantelo ' s money had been transferred out of his bank account after his disappearance . Cantelo ' s family tried to find William but with no real success . They employed a private investigator who traced him to America but could not find out anything more . Subsequent rumours and speculations . An American electrical engineer , Hiram Maxim , had moved to London and perfected a rapid - fire machine gun . Cantelo ' s two sons happened across a photograph of Maxim , whose similarity to their father led them to believe that he was still alive and had assumed a new identity . Descriptions of the gun sounded similar to the one they had worked on . The sons tried to challenge Maxim but he wanted nothing to do with them . He sold the Maxim gun to the British government . The name " Maxim " , the family claimed , was evidence that Cantelo had assumed this new identity . Fond of maxims , Cantelo often carried a book of such phrases in his pocket . Two witnesses also claim that Cantelo referred to his invention as " my maxim gun " . The family ' s belief that Cantelo re - emerged under a new identity is inconsistent with accounts of Maxim ' s early life . Born in 1840 , Maxim became a carriage maker ' s apprentice at the age of 14 . He developed an interest in inventions and obtained 271 patents , the first of which came in 1866 . An episode of " Punt PI " , a BBC Radio 4 series , covered the Cantelo story with Steve Punt investigating Cantelo ' s disappearance . He discovered that Maxim had complained about a man who was impersonating him in America . He also showed a photograph of Cantelo next to his machine gun to the Royal Armouries , who stated that the weapon appeared to be the same as the Maxim gun . A facial expert who compared the images of Cantelo and Maxim highlighted that there were visible differences between the two men . Punt cast doubt on the idea that Cantelo and Maxim were the same person but noted the coincidences .