This book is a companion to Patrick Colquhoun's report arguing for the establishment of a regular police force in London (RCIN 1141074). It was presented to George III by the author in 1800 and analyses the effect of petty and organised crime on trade on the River Thames. Colquhoun estimated that almost £10 million was lost per year to criminal activities on the river: a vast sum of money. The work also briefly explores the history of trading on the Thames, the companies which served the river and its importance to the London, and wider British, economy, through employment and through imports and exports. Colquhoun and his associates in London established an irregular police force, the "River Police" in 1798 to try to combat some of the problems facing London at this time, not just on the river, but in the wider city. The success of the force persuaded the government to pass an act which made it a public organisation in 1800, one of the first such police forces to be established and which pre-dated Robert Peel's police force by almost 30 years.