History of Navigation

Map of Magnetic Variation

This map shows not only the lines of magnetic variation in North America, but also the approximate location of the north magnetic pole.

Called "The Variation of the Compass for the Year 1955," it is from Bowditch's "American Practical Navigator," H.O. Pub. No. 9, 1962, p. 163. Penobscot Bay's variation is approximately 18 degrees west.

Modern Compass Rose

This compass rose, appearing on a 1993 chart, Penobscot River, NOAA Number 13309 , gives directions in degrees, but points are still included. It has three concentric roses, one for true directions and two for magnetic directions with the inner one graduated in points of 11 1/4 degrees. The inner roses have been set to the local magnetic variation of 18 degrees west.

Meridians of Longitude

Illustration showing how longitude lines cut the globe in planes that intersect at the polar axis. Longitude is a measurement that identifies a location as being a certain distance east or west of a prime meridian. Penobscot Marine Museum is located 68 degrees 55 minutes west of the Prime Meridian which passes through Greenwich, England.

This illustration is from Bowditch's American Practical Navigator, H.O. Pub. No. 9, 1975, p. 444.

Parallels of Latitude

Illustration showing how latitude lines cut the globe in parallel planes, with the longest latitude line being the equator. Latitude is a measurement that identifies a location as being so far north or south of the equator. Penobscot Marine Museum is located 44 degrees 27 minutes north of the equator.

This illustration is from Bowditch's American Practical Navigator, H.O. Pub. No. 9, 1975, p. 445.

Chart of Belfast Bay, 1882

This is a detail of the Penobscot River and Belfast Bay Maine chart, published by the U.S. Coast Survey in 1882. Details on the chart include where there are and aren't trees, as well as the first bridge at the head of the harbor. The granite beacon on Steel's Ledge at the mouth of the harbor is still in position, but now there is a bell buoy off the ledge that marks the harbor entrance.

The bridge at the head of harbor is the first one; a second one followed in 1923, and an elevated bridge was built in the 1960s. The 1923 bridge is now a footbridge.

Wright's Chart of the World, 1599

Map of the World, Edward Wright, 1599

Published by Richard Hakluyt in his Principal Navigations in 1600, this world map summarizes European navigational knowledge. It is honest, without myth and hypothesis. Most importantly for navigators like Bartholomew Gosnold, Matthew Pring, George Waymouth, and John Smith, it incorporates Wright's improvements to Mercator's projections published in his Certaine Errors in Navigation...

University of Virginia Map Library Collection

Sailing Directions, Muscle Ridge Channel, 1822

These are sailing directions for bypassing the Muscle Ridge Channel and sailing up the main route of Penobscot Bay, the same route that large vessels take today. These were published by Edmund G. Blunt in the 1822 edition of the American Coast Pilot. When you read them, you will note that the names of many of the places have changed. Brigadier Island is now Sears Island. Long Island is now Isleboro. There were no up-to-date charts showing detail of the area, so sailing directions were particularly important.

Wheelhouse on Dragger "E.G. Winters"

The dragger E.G. Winters was built at the Harvey F. Gamage shipyard in South Bristol, Maine, in 1976. This photo shows the central position of a radar unit. A corner of a radio shows on the left. Today's wheelhouse would have a plotting depth finder, a GPS unit, an auto pilot, and aboard a fishing vessel, a fish finder.

"Red" Boutilier took this picture as he reported on fishing vessel construction in the 1970s.

Pa and Mate Taking the Sun aboard the Bark Carrie Winslow

Every good day at sea includes taking a sun sight at noon, to find the vessel's latitude. With a good chronometer, one can also find one's longitude. Here Capt. Adelbert Montgomery and the First Mate are "shooting the sun" or getting the sun's altitude using a sextant.

The photograph was taken by the captain's daughter, Ruth Montgomery aboard the Portland owned bark Carrie Winslow in 1898.

North Atlantic Chart Showing Ship Track

Capt. Henry A. Starrett kept a track on his North Atlantic chart of where he was going, as he sailed the ship Levi G. Burgess back and forth to Europe. This track, which is kept up once a day, shows that the wind is not always in favor of getting the ship home most directly.

The Burgess was a Thomaston built and owned Down Easter built in 1877 and sold into the Pacific Coast trades in 1887 and then into the salmon business in 1910, where she worked until broken up in 1928.


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