One theory has it that the bell was named after a popular heavyweight boxer Benjamin Caunt. However, the consensus today seems to be that it was named after Sir Benjamin Hall*, a (literally) weighty politician of the time who was the Parliamentary Commissioner of Works.
* IMPORTANT: due to restrictions, Atlas may not be able to offer Travel Cover to certain destinations if they are deemed a war-zone and/or if HM Foreign & Commonwealth Office recommends no travel to the area/region/country.