During the time he helped to found and forge the Geological Society , Greenough served in the militia in the Light Horse Volunteers of London and Westminster . This was a corps of volunteers , originated by a group of city businessmen , and rather than being paid for their services members had to pay to join and maintain an annual subscription . The unit has an obligation to be called out in support of the civil power when necessary . It was rather different from other regiments in organising itself democratically through a committee . All prospective members had to be proposed by one of the committee and if admitted all served as private soldiers , with officers elected by ballot . Greenough enlisted as a private soldier in 1803 , but in 1808 he was elected a commissioned officer with the rank of Lieutenant and he served for the next 11 years . Greenough resigned his commission in 1819 as a matter of principle following the Peterloo massacre in Manchester , which he regarded as an abuse of military power for political ends . He published his resignation letters in The Morning Chronicle and The Times . Clearly , Greenough was a man of conscience
Peterloo massacre
Peterloo Massacre
George Bellas Greenough