<P> From the Metropolitan Police's foundation, the force had relied on the use of hand rattles for officers to signal the need for assistance . In 1884 the Home Secretary invited competition from many companies to invent a "police whistle" to replace the rattle . J. Hudson & Company of Birmingham were awarded the contract for 7,175 whistles at the price of 11d each . At the same time, a competition for the contract to supply the Metropolitan Police with new truncheons was under way . This contract was won by Ross & Company, who supplied the Metropolitan Police with Lignum vitae truncheons . In 1886, during a riot between warring working parties in Hyde Park, many truncheons were damaged or broken, samples were sent off to be tested by the Royal Army Clothing Department, at a cost of 16 shillings per day . In October 1886, 900 pounds worth of Lance and Cocuswood were purchased, to use in place of Lignum vitae that was deemed unsuitable after Army testing . </P> <P> Since the MPS's inception, the force has been headed by a Commissioner, rather than a Chief Constable which is the highest rank in police forces outside London . The first Commissioners to hold the post were Lieutenant - Colonel Sir Charles Rowan and Sir Richard Mayne . When Sir Charles Rowan died, leaving Sir Richard Mayne as the surviving Commissioner, Captain William Hay was drafted in to jointly run the force with Mayne . However, because the two Commissioners did not agree on methods of running the force, since 1855 it was decided that only one Commissioner would run the force . </P> <P> Metropolitan Police patrols took to the streets on 29 September 1829, despite resistance from certain elements of the community who saw them to be a threat to civil liberties . The initial force consisted of two Commissioners, eight Superintendents, 20 Inspectors, 88 Sergeants and 895 Constables . Patrolling the streets within a seven - mile (11 km) radius of Charing Cross, in order to prevent crime and pursue offenders . Between 1829 and 1830, 17 local divisions each with its own police station were established, each lettered A to V, allocating each London borough with a designated letter . These divisions were: A (Westminster); B (Chelsea); C (Mayfair and Soho); D (Marylebone); E (Holborn); F (Kensington); G (Kings Cross); H (Stepney); K (West Ham); L (Lambeth); M (Southwark); N (Islington); P (Peckham); R (Greenwich); S (Hampstead); T (Hammersmith) and V (Wandsworth). In 1865 three more divisions were created, W (Clapham); X (Willesden) and Y (Tottenham); J Division (Bethnal Green) was added in 1886 . </P> <P> On 28 June 1830, Constable Joseph Grantham became the first member of the force to be killed in the line of duty, an incident described by the Coroner's Inquest as "justifiable homicide". Other indications of the Constabulary's unpopularity of the time, were such nicknames as' Raw Lobsters',' Blue Devils' and' Peel's Bloody Gang' . Officers were physically assaulted, others impaled, blinded, and on one occasion held down while a vehicle was driven over them . </P>

When did the metropolitan police force become a service