In 1633 a cartographer was appointed to the States-General of Holland, and it was his duty to correct the charts from the ships' logs. The Dutch at an early date made important progress in publishing charts. In 1720 there was established in Paris by order of the king, a central chart office ("dépôt des cartes et plans, journaux et mémoires concernant la navigation"), and in 1737 the first charts were published by this office. Detailed surveys of the coast of France were commenced in 1816. In 1740 "the commissioners for the discovery of longitude at sea" were authorized by Parliament to expend money on the survey of the coasts of Great Britain, this commission having been created in 1713. Various rewards were offered by this commission, including one of £10,000, for the discovery of a method of determining the longitude within 60 miles, an interesting side light on the uncertainties of navigation at that time. Compensated timepieces, which have been so important a factor in improving navigation, were invented by Harrison about 1761. [Illustration: FIG. 3. LOXODROMIC CHART OF NORTH ATLANTIC OCEAN, 1565. A PLAIN CHART WITH LATITUDE DEGREES OF EQUAL LENGTH.] In 1795, by an Order in Council, a Hydrographical Office was established in London, "to take charge and custody of such plans and charts as then were, or should thereafter be, deposited in the Admiralty, and to select and compile such information as might appear to be requisite for the purpose of improving navigation." This office had at first one assistant and one draftsman. Before that time many charts of a private or semiofficial character had been published; the catalogue of the East India Company in 1786 included 347 charts. In 1807 the Congress of the United States authorized the President "to cause a survey to be taken of the coasts of the United States, in which shall be designated the islands and shoals, with the roads or places of anchorage, within twenty leagues of any part of the shores of the United States; and also the respective courses and distances between the principal capes, or headlands, together with such other matters as he may deem proper for completing an accurate chart of every part of the coasts within the extent aforesaid." This law was the origin of the present United States Coast and Geodetic Survey, now under the Department of Commerce and Labor. In 1841 a systematic survey of the Great Lakes was commenced; this is the Survey of the Northern and Northwestern Lakes, briefly known as the Lake Survey, conducted under the Corps of Engineers.