In 1714 the British "Commissioners for the discovery of longitude at sea" came into prominence. This group, which existed until 1828, offered grants and rewards for the solution of navigational problems. Between 1737 and 1828, the commissioners disbursed some £101,000. The government of the United Kingdom also offered significant rewards for navigational accomplishments in this era, such as £20,000 for the discovery of the Northwest Passage and £5,000 for the navigator that could sail within a degree of latitude of the North Pole. A widespread manual in the 18th century was "Navigatio Britannica" by John Barrow, published in 1750 by March & Page and still being advertised in 1787.