Lieut.enant Matthew Fontaine Maury is renowned for his work collecting ships' logs and gathering information around the world about wind and current patterns at different times of the year. As a result of this work, he was able to compile the information into a graphical form called a Pilot Chart. This early version provides wind information for each 1 degree by 1 degree area of the ocean around Cape Horn. The information helped captains determine the most efficient and safe routes to get to their destinations.
The New American Practical Navigator has been the navigator's bible for two hundred years, since its first publication in 1802. It was originally published by Edmund March Blunt and then by his sons. After the Civil War, the Blunts sold copyright to the U.S. Government, and it has since been a publication of the Hydrographic Office, now part of NOAA, as H.O. #9.
Though Thomas Jefferson founded the U.S. Coast Survey, it was not until 1874 that there were published sailing directions for the East Coast. Until then, navigators relied on the privately-printed sailing directions by Blunt. The government publication included many more charts and illustrations to aid the navigator than Blunt's sailing directions offered; however, the Blunt company stayed heavily involved in the navigation publishing business.
Most of the captains coasting New England in the 1870s and 80s would have had this book aboard.
London chart publisher James Imray was known as one of the best makers of "blueback" charts, those charts so large that they required a backing piece of paper to support the two or three sheets of printed chart paper. These were commonly found in the chart collections of Maine ship masters as they provided world wide coverage. This chart is of the North Pacific Ocean published in 1875.
Mechanical depth sounder, which works like a log, with a spinning impeller measuring depth as it drops through the water column. A release keeps the impeller from turning as the sounder is pulled back up. One gauge measures from 2 to 30 fathoms and the other from 30 to 150 fathoms. Like the patent log, this was also invented by Walker. Patent number 8486 G is engraved on the sounder.
This mechanical log tells the distance the ship sails through the water by recording the number of times the five-finned section of the mechanism turns. The indicator shows nautical miles sailed, in hundreds, tens, and ones. The log was towed astern of the ship and hauled in for readings. Though not perfect, the harpoon log was significantly more accurate than the traditional chip log and sand glass. This instrument was patented September 18, 1866.
Lunar distance was a complex but important means of determining longitude at sea. It remained useful throughout most of the 19th century as many ship captains could not afford expensive chronometers. Using lunars, longitude could be found with nothing but tables and a octant or sextant. Bowditch was important in navigational history in part because he came up with easier methods for solving lunar distance sight reductions.
This passage is from Bowditch's New American Practical Navigator, 1868, p. 231.
The Mariners Mirrour was the English translation by Anthony Ashley of the Dutch Spieghel der Zeevaerdt by Lucas Janszoon Wagenaer. Published in 1588, it provided, within a single book, a treatise on navigation, sailing directions, and the latest charts for most of Europe. It was so important, and its Dutch creator so well recognized that these types of navigational publications became known in England as "Waggoners."
The title page shows the instruments of a navigator of 1588:
This diagram illustrates how the moon appears to move through the stars. It shows that there is a difference between the measured altitude of the moon and its actual altitude, due to atmospheric refraction. Locations of the moon are shown at 3 and 6 hours, to show its actual position as given in the Nautical Almanac, and that its observed position must be interpolated between the given positions. From: Man is Not Lost; A Record of Two Hundred Years of Navigation with the Nautical Almanac, 1767-1967,
John Harrison (1693-1776) was the English clockmaker who designed and built the first successful chronometers, clocks accurate enough to take to sea to measure longitude. He began his work in 1730 with the first sea trial in 1736. After 5 versions of his chronometer, he satisfied Britain's Board of Longitude government, earning some 23,000 pounds which he had recieved in increments as partial payments for various versions. The Board never did award him their full 20,000 pound prize.