Ship's log register or recorder, used to determine the distance a ship travels and the speed it is traveling. It would be fixed to the rail (taffrail) at stern of the ship and attached to the log rotor that would be towed behind the ship. The Cherub design was one of the first to have the register placed on the ship instead of with the rotor in the water.Ship's taffrail log register, recovered from the tug "Melbourne". Dial and bracket, brass. "Patented and made in England". Parts of words 'Walker's Cherub Log, Mark II" are visible. 2 dials marked in 100's and 10's "Patented and made in England". Parts of words "W" (Walker) "CH" (CHERUB) "Ma" (Mark III) flagstaff hill, warrnambool, shipwrecked coast, flagstaff hill maritime museum, maritime museum, shipwreck coast, flagstaff hill maritime village, great ocean road, ship's log register, log register, log dial, t walker, thomas walker, cherub log

The Excelsior IV Log is a nautical instrument for measuring a vessel’s speed and distance travelled. When navigating a ship it is essential to be able to estimate the boat’s speed and distance travelled to determine its position at sea. In times past the only way to measure a ship’s speed was to throw a wood log into the water and observe how fast it moved away from the ship. In the 16th century, the log was fastened to a rope knotted at set intervals. The log was thrown over the stern (back) of the vessel and a crew member counted the number of knots that were paid out in a set time. From this, they could estimate the speed of the vessel through the water. This was known as streaming the log and is also the derivation of the knot as a measurement of nautical speed. The Walker’s Excelsior Mark IV instrument was designed for smaller vessels, such as yachts, launches and fishing vessels. Historical: Thomas Walker & Son was internationally renowned in the manufacturing of ships logs, founding father , Thomas Walker (1805–1871), an engineer in Birmingham, patented a mechanical log in 1878 which was a recording instrument that attached to a rail at the stern of a vessel connected by a long cord with a rotor which was towed behind the ship. The instrument dial recorded the distance travelled. Thomas Walker first went into business to manufacture stoves at 58 Oxford Street Birmingham. Walker’s self-feeding stove was widely lauded at the Paris Exhibition of 1855, winning a prize medal and kick starting the first of many notable innovations for the Walker family's manufacturing business. However, it wasn’t until working on an earlier ship’s log model invented by his Uncle that Thomas Walker became interested in the further development of this device, used to ascertain a ship’s speed. Walker continued to improve on the common log for the company of Massey & Sons and these improvements were deemed revolutionary. This log became a firm favourite of the West India Association (British-based organisation promoting ties and trade with the British Caribbean), being the most common log in use for two generations. It took until 1861 for Thomas Walker and his son, Thomas Ferdinand Walker (1831-1921) to patent the first Walker log of many. Together, with the introduction of the A1 Harpoon Log two years later, they established the Walker Log Business as a force to be reckoned with. By the time of his passing in 1871, Thomas Walker Snr had not only founded a family business with considerable staying power but also instilled a tradition of public service. Having sat as a representative on the Birmingham Town Council for 15 years and played an active role in public works, he was soon given the nickname of ‘Blue Brick Walker’. Much like his father, Thomas Ferdinand Walker changed the face of the maritime industry. His patent of 1897, the ‘Cherub’ log, was a notable departure from the past providing a far more accurate reading and replacing the majority of logs of the age. They were the first to produce an electric log and the Walker factory was one of the first to introduce the 48 hour work week for employees. The ship log was invented and made by a significant marine instrument maker and innovator of machinery. It demonstrates the huge leap taken to improve navigational accuracy at sea with an instrument that was in use for decades.Ship's Taff Rail Log, rope attached. Walker's Excelsior IV Log model. Nautical miles dials: units and 10's. "Walker's Excelsior IV Log", "Made in England by Thomas Walker, Birmingham"flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, log register, taff rail log, taffrail log, marine navigation, a1 harpoon log, cherub’ log, walker’s excelsior mark iv log, ship’s log instrument, mechanical ship’s log, measure ship’s speed, nautical instrument, navigation instrument, massey & sons, thomas walker, blue brick walker, thomas walker & son, thomas ferdinand walker, 48 hour work week

Thomas Walker & Son was internationally renowned in the manufacturing of ships logs. Founding father Thomas Walker (1805–1871), an engineer in Birmingham, patented a mechanical log in 1878 which was a recording instrument that attached to a rail at the stern of a vessel connected by a long cord with a rotor which was towed behind the ship. The instrument dial recorded the distance travelled. Thomas Walker first went into business to manufacture stoves at 58 Oxford Street Birmingham. Walker’s self-feeding stove was widely lauded at the Paris Exhibition of 1855, winning a prize medal and kick starting the first of many notable innovations for the Walker family's manufacturing business. However, it wasn’t until working on an earlier ships log model invented by his Uncle that Thomas Walker became interested in the further development of this device, used to ascertain a ship’s speed. Walker continued to improve on the common log for the company of Massey & Sons and these improvements were deemed revolutionary. This log became a firm favourite of the West India Association (British-based organisation promoting ties and trade with the British Caribbean) and the most common log in use for two generations. It took till 1861 for Thomas Walker and his son, Thomas Ferdinand Walker (1831-1921) to patent the first Walker log of many. Together, with the introduction of the A1 Harpoon Log two years later, they established the Walker Log Business as a force to be reckoned with. By the time of his passing in 1871, Thomas Walker Snr had not only founded a family business with considerable staying power but also instilled a tradition of public service. Having sat as a representative on the Birmingham Town Council for 15 years and played an active role in public works, he was soon given the nickname of ‘Blue Brick Walker’. Much like his father, Thomas Ferdinand Walker changed the face of the maritime industry. His patent of 1897, the ‘Cherub’ log, was a notable departure from the past providing a far more accurate reading and replacing the majority of logs of the age. They were the first to produce an electric log and the Walker factory was one of the first to introduce the 48 hour work week for employees. This ship log was invented and made by a significant marine instrument maker and innovator of machinery. It demonstrates the huge leap taken to improve navigational accuracy at sea with an instrument that was in use for decades. Ship Log, three analogue dials calibrated in increments of Miles, the Rocket Log is a nautical instrument for measuring a vessel’s speed and distance traveled. The floating log was drawn behind the ship over a fixed time period in order to measure the distance traveled. The counter could measure enough miles to cover the maximum distance traveled by a ship in one day. The log has two distinct parts; a brass register, made by Walker, showing the distance recorded and the rotator made by Reynolds, that spins in the water driving the counter. both parts are connected by a linked chain. The register has a cylindrical brass body approx 4.5 cm diameter containing registering mechanism with hardened steel bearings. Distance is indicated by the three pointers on enamel plate as follows: graduated every 10 miles from 0-100; every mile from 1-10; every 1/4 mile from 1/4 -1. A brass sling and eye secured to the body enables it to be attached to the taffrail. The original rotator would have had a cylindrical tapered wooden body, approx 4.5 cm in diameter with three metal alloy fins or could be all made from brass. A towing eye is fitted to the tapered end. The two pieces of apparatus are connected by a length of linked chain, length 22.9 cm."Walkers Rocket Ship-Log Birmingham (Patented)" printed on face-plate. "Made by Thomas Walker".flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, ship log, rocket log, mechanical ship log, measuring instrument, marine instrument, nautical instrument, speed recording instrument, ship log register, walker ship log, walkers rocket ship-log, thomas walker, thomas walker & son, thomas ferdinand walker, walker log business, reynolds ship log rotor, taffrail log, taff rail log, west india association

Thomas Walker & Son was internationally renowned in the manufacturing of ships logs, founding father, Thomas Walker (1805–1871), an engineer in Birmingham, patented a mechanical log in 1878 which was a recording instrument that attached to a rail at the stern of a vessel connected by a long cord with a rotor which was towed behind the ship. The instrument dial recorded the distance travelled. Thomas Walker first went into business to manufacture stoves at 58 Oxford Street Birmingham. Walker’s self-feeding stove was widely lauded at the Paris Exhibition of 1855, winning a prize medal and kick starting the first of many notable innovations for the Walker family's manufacturing business. However, it wasn’t until working on an earlier ships log model invented by his Uncle that Thomas Walker became interested in the further development of this device, used to ascertain a ship’s speed. Walker continued to improve on the common log for the company of Massey & Sons and these improvements were deemed revolutionary. This log became a firm favourite of the West India Association (British-based organisation promoting ties and trade with the British Caribbean). and the most common log in use for two generations. It took till 1861 for Thomas Walker and his son, Thomas Ferdinand Walker (1831-1921) to patent the first Walker log of many. Together, with the introduction of the A1 Harpoon Log two years later, they established the Walker Log Business as a force to be reckoned with. By the time of his passing in 1871, Thomas Walker Snr had not only founded a family business with considerable staying power but also instilled a tradition of public service. Having sat as a representative on the Birmingham Town Council for 15 years and played an active role in public works, he was soon given the nickname of ‘Blue Brick Walker’. Much like his father, Thomas Ferdinand Walker changed the face of the maritime industry. His patent of 1897, the ‘Cherub’ log, was a notable departure from the past providing a far more accurate reading and replacing the majority of logs of the age. They were the first to produce an electric log and the Walker factory was one of the first to introduce the 48 hour work week for employees. This ship log rotor was invented and made by a significant marine instrument maker and innovator of machinery. It demonstrates the huge leap taken to improve navigational accuracy at sea with an instrument that was in use for decades and still is today. Therefore it is a worthy addition to the Flagstaff Maritime collection as it demonstrates another aspect of maritime navigation.A Walkers Cherub III Patent mechanical ship brass rotor with with four vane's one marked with an anchor and "T. W. Cherub 441", The log is attached to a brass swivel with a short length of rope. Has T W Cherub 441 marked on a vane.flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, log rotor, taffrail log, thomas walker, marine technology, marine instrument, navigation, ship speed, measurment

The John E. Hand & Sons Company was founded in Philadelphia in 1873, quickly gaining a reputation as competent manufacturers of nautical instruments and compass adjusters. In fact, John Enos Hand, the company founder, is recognised as the first man in America to adjust a compass aboard an iron ship. The Hand Company built navigational equipment for all varieties of floating vessels, and operated a chain of retail outlets with “service stations” in numerous port cities, including Baltimore and New Orleans, until 1956. Service stations sold Hand instruments as well as other nautical paraphernalia and provided compass adjusting services. Additionally, John E Hand and his two sons, John L Hand and Bartram Hand, were inventors in their own right who patented design improvements for numerous instruments that were employed in the company’s work. Commercial and private contracts dominated the firm’s business until the late 1930s when the United States military began preparations for World War II. Although the Hand Company never completely abandoned its involvement with private industry, after World War II, military contracts monopolised their business. The Company obtained contracts with the Navy, Coast Guard and Marines to develop new instruments, and to build military-engineered nautical equipment. Of note are the wrist compass, developed for the Navy beginning in the 1950s, and the Mark VII Model 5 Navy Standard Binnacle. Although it moved numerous times, the Hand Company headquarters and factory remained in the Delaware Valley, occupying several buildings in Philadelphia and southern New Jersey. Maintaining its central office in Philadelphia well into the 1900s, the factory was moved to Atco, New Jersey around the turn of the twentieth century and subsequently to Haddon field, New Jersey. It moved one last time in the 1960s to Cherry Hill, New Jersey. In 1997, California-based Sunset Cliffs Merchandising Corporation purchased the Hand Company and all its assets for $100,000. "HAND" brand taffrail log by John F. Hand and Sons Co. Register is enclosed in log, has a glass front and 3 dials on an enameled surface, the first dial registers the miles up to 100, the second registers the units up to 10 mile, the third registers quarters of a mile. The item is rocket shaped with a three blade rotor and a rope ring attachment at one end; the rotor will spin when a rope is attached, allowing the apparatus dials to measure the ship's speed when it is dragged behind a ship. Diagram of the 'Hand' trademark with a compass card in the middle, inscription reads "John F Hand and Sons Co" and "PHILA-BALTO" ( Abbreviation for: Philadelphia / Baltimore) flagstaff hill, warrnambool, shipwrecked coast, flagstaff hill maritime museum, maritime museum, shipwreck coast, flagstaff hill maritime village, great ocean road, bartram hand, john enos hand, john f. hand and sons co, john l hand, john hand & sons instrument makers, john hand & sons of philadelphia, marine instrument, marine service station, mechanical ship log, nautical instrument, nautical navigation, navigational equipment, scientific instrument, ship log, ship log register, ship’s speed, sunset cliffs merchandising corporation, speed log, rocket log, harpoon log, taffrail log, taff rail log

In times past the only way to measure a ship’s speed was to throw a wood log into the water and observe how fast it moved away from the ship. In the 16th century, the log was fastened to a rope knotted at set intervals. The log was thrown over the stern (back) of the vessel and a crew member counted the number of knots that were paid out in a set time. From this, they could estimate the vessel's speed through the water. This was known as streaming the log and is also the derivation of the knot as a measurement of nautical speed. Various manufacturers of nautical equipment had sought over the years to perfect the operation of determining a ship's speed and it wasn't until Thomas Walker and his son Ferdinand developed a mechanical system that eventually made this task became easy for marine navigators. Thomas Walker & Son were internationally renowned in the manufacturing of ship logs the founding father, Thomas Walker (1805–1871), an engineer in Birmingham, patented his mechanical log in 1878 which was a recording instrument that attached to a rail at the stern of a vessel connected by a long cord with a rotor which was towed behind the ship. The instrument dial then recorded the distance travelled. Thomas Walker first went into business to manufacture stoves at 58 Oxford Street Birmingham. Walker’s self-feeding stove was widely lauded at the Paris Exhibition of 1855, winning a prize medal and kickstarting the first of many notable innovations for the Walker family's manufacturing business. However, it wasn’t until working on an earlier ship’s log model invented by his Uncle that Thomas Walker became interested in the further development of this device, used to ascertain a ship’s speed. Walker continued to improve on the common log for the company of Massey & Sons and these improvements were deemed revolutionary. This log became a firm favourite of the West India Association (a British-based organisation promoting ties and trade with the British Caribbean), being the most common log in use for two generations. It took until 1861 for Thomas Walker and his son, Thomas Ferdinand Walker (1831-1921) to patent the first Walker log of many. Together, with the introduction of the A1 Harpoon Log two years later, they established the Walker Log Business as a force to be reckoned with. By his passing in 1871, Thomas Walker Snr had not only founded a family business with considerable staying power but also instilled a tradition of public service. Having sat as a representative on the Birmingham Town Council for 15 years and played an active role in public works, he was soon given the nickname of ‘Blue Brick Walker’. Much like his father, Thomas Ferdinand Walker changed the face of the maritime industry. His patent of 1897, the ‘Cherub’ log, was a notable departure from the past providing a far more accurate reading and replacing the majority of logs of the age. They were the first to produce an electric log (Trident) and the Walker factory was one of the first to introduce the 48-hour work week for employees.The ship log was invented and made by a significant marine instrument maker and innovator of machinery. It demonstrates the huge leap taken to improve navigational accuracy at sea with an instrument that was in use for decades.Ships Log, Walker Trident electric motor, in wooden box with instructions inside box. The motor dial with electric cord is still inside box.Inscription "Admiralty patent number 3332" and "Walker Trident Electric Ship Log (Mark III), 15-25 volt". On top of lid, hand written, is "G TAYLOR"flagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, ships log, thomas walker & son, electric ships log, marine navigation, thomas ferdinand walker, ship log

John Bliss (1795-1857) was born in Connecticut, trained as a silversmith and clock maker in Vermont, and began in business as a jeweller in New York around 1830. In 1834, now trading as Bliss & Creighton, he made and marketed chronometers and other items for navigational use. The firm became John Bliss & Son in 1855 and John Bliss & Co. in 1857. It remained in business until 1957. Truman Hotchkiss, a sea captain from Stratford, Connecticut, designed a mechanical Taff rail log in which the recording mechanism was placed on taffrail (or upper part of the stern) of the ship. After acquiring the rights to Hotchkiss’s patents of 1864 and 1867, John Bliss & Co. began advertising the "American Patent Taffrail Log." The firm also offered mechanical logs based on patents granted to John Bliss, Jnr and his brother George, as well as English instruments based on Massey’s and Walker’s patents.The SPECULANT is historically significant as the largest ship to have been registered in Warrnambool, and is believed to have been the largest barquentine to visit Melbourne. It is evidence of the final days of large commercial sailing vessels involved in the Victorian and New Zealand timber trade. The SPECULANT is listed on the Victorian Heritage Register VHR S626John Bliss Taffrail ship log incomplete, rope and spinner missing used on the vessel "Speculant " ( See "Notes" at the end of this document for further information) "Taffrail Log Patented Nov .. Apr .. June .. Sep 1.", dial registers 1/4, units and 10's. with 3 sets of dials, 2 with hands missingflagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, la bella, speculant, cumming and ellis, international timber trade, p. j. mcgennan and co. warrnambool, capt. james jacobsen, first mate: james munro, second mate: john scerling;, cook: b bond; a. b., s: v. sundring, s: h. hansen, s: b. melson, s: h. johnston, s: t. trumblen;, ordinary seaman: r. thompson, cape patton, c. ramsden, log, taffrail ship's log, ship log, john bliss, patent log, peter mcgennan

The ship's log part, called a fish, is likely to be from a mechanical taffrail log system. It was recovered from the wreck site of the barque, the 1840-1852 Grange. There are no marks on the fish to identify its maker or model. It is part of the John Chance Collection. This ‘fish’ is part of an early to mid-1800s ship's log. It would likely have been part of a taffrail log connected to a rotor (also called propeller, spinner) by a strong line, and the other end connected by a line to a dial mounted on the taffrail, or stern rail, at the stern of the vessel. As the propeller rotated through the water it would spin the log, which in turn would cause a number to register on the dial, showing the current speed in knots; one knot equals one nautical mile per hour. TAFFRAIL LOGS A taffrail log is a nautical instrument used for measuring the speed of a vessel, providing vital navigational information to be calculated, such as location and direction. A log has been used to measure the speed of a vessel since the 1500s. A simple piece of wood was tied to a long line and thrown into sea at the back of the vessel. The rope was knotted all along at equal distances apart. On a given signal the log line was pulled back into the vessels, the knots counted until the log came up, then the figures were calculated by a navigator In 1802 the first successful mechanical log available for general use was invented by Edward Massey. It had a rotor 'V' section connected to a recording mechanism. The water’s movement rotated the rotor, which intern sent the movement to the recorder. There are examples of this invention available to see in some of the maritime museums. Thomas Walker, nephew of Edward Massey, improved on Massey’s design, and Walker and his son took out a patent on the A1 Harpoon Log. In 1861. Both Massey and Walker continued to improve the designs of the taffrail log. New designs were still being introduced, even up to the 1950s. THE GRANGE, 1840-1858- The wooden barque ’Grange’ was a three-masted ship built in Scotland in 1840 for international and coastal trade. On March 22, 1858, the Grange set sail from Melbourne under Captain A. Alexander, carrying a cargo of ballast. The barque had left the Heads of Phillip Bay and was heading west along the Victorian coast towards Cape Otway. The ship struck Little Haley’s Reef at Apollo Bay due to a navigational error and was stuck on the rocks. The crew left the ship carrying whatever they could onto the beach. Eventually, the remains of the hull, sails and fittings were salvaged before the wreck of the Grange broke up about a month later. About 110 years later, in 1968, the wreck of the Grange was found by divers from the Underwater Explorers Club of Victoria. They were amazed to find a unique, six to nine pound carronade (type of small cannon) and a cannonball on the site. There have been no other similar carronades recorded. In that same year the anchor of the Grange was recovered by diver John Chance and Mal Brown. The ship’s log is significant historically as an example of hardware used when building wooden ships in the early to mid-19th century. The ship’s log is historically significant as an example of the work and trade of blacksmith. The ship’s log also has significant as it was recovered by John Chance, a diver from the wreck of the Grange in the 1968. Items that come from several wrecks along Victoria's coast have since been donated to the Flagstaff Hill Maritime Village’s museum collection by his family, illustrating this item’s level of historical value. The ship’s log is historically significant for its association with the 1840s wooden barque, the Grange. The Grange is an historical example of a Scottish built vessel used for international and coastal trader of both cargo and passengers in the mid-19th century. The Grange is an example of an early ship, designed with a wooden hull. It is significant as a ship still available to divers along the south coast of Victoria, for research and education purposes. The Grange is an example of a mid-19th century vessel that carried a weapon of defence onboard. Ship log fitting, called a fish; part of a brass navigational instrument, likely to be from a taffrail log. The metal is a tan colour and has rough surface with a sheen, and discolouration in places. Its basic shape is a hollow cylinder with ends tapering to a smaller size. In the centre there are opposing openings cut out, showing a rough texture inside. One end on the cylinder is closed with a ring and shank installed, fixed by an embedded screw through the end of the cylinder. There are no inscriptions.flagstaff hill, warrnambool, flagstaff hill maritime museum, maritime museum, shipwreck coast, flagstaff hill maritime village, great ocean road, west coast trader, apollo bay, mid-19th century shipwreck, the grange, scottish barque, little henty reef, captain a alexander, underwater explorers club of victoria, vhr 5297, coastal trader, wooden shipwreck, john chance, wooden ship, taffrail log, marine instrument, marine technology, navigation, nautical instrument, mechanical log, nautical navigation, navigation equipment, scientific instrument, ship log, ship log register, ship speed, taff rail log, patent log, towed log, taffrail log fish, edward massey, thomas walker

A Ship's Log looked very similar to a torpedo but was used to measure the speed of a ship. When dragged behind the vessel, movement of water past the propeller caused it to rotate, turning the small needle dials to record the distance and speed travelled. https://museumsvictoria.com.au/immigrationmuseum/resources/journeys-to-australia/Ship's Log Display HeadWalkers Cherub 111 ships lognavigation, speed, knot, chip log, log, thomas walker and son

Bifold grey card -Radio Log Card - issued by Hartley's sports stores Mitchell Street Bendigo. The card lists radio stations across Australia including the dial numbers, wave length and location.business, retail, hartleys

From Scarborough Maritime Heritage Centre: A Yacht Log was a nautical instrument for measuring a vessel's speed and distance travelled. When navigating a ship it is essential to be able to estimate the boat's speed and distance travelled to determine its position at sea. In times past the only way to measure a ship's speed was to throw a wood log into the water and observe how fast it moved away from the ship. In the 16th century, the log was fastened to a rope knotted at set intervals. The log was thrown over the stern (back) of the vessel and a crew member counted the number of knots that were paid out in a set time. From this they could estimate the speed of the vessel through the water. This was known as streaming the log and is also the derivation of the knot as a measurement of nautical speed. In 1878, Thomas Ferdinand Walker (1837–1921), an engineer in Birmingham, patented a mechanical log in which a recording instrument was attached to a rail at the stern of a vessel connected by a long cord with a rotor which was towed behind the ship. The instrument dial recorded the distance travelled. The 'Log' at the Heritage Centre was recovered from a skip in Scarborough and was one of the first artefacts collected by the volunteer group. It is made of brass with a ceramic dial, with the main scale marked from 0 to 100 nautical miles and an inset dial marked from 0 to 10 miles. It has a fixing plate, on which it can turn, with which it would have been attached to the 'taffrail', the rail at the stern of a ship, usually on the starboard side. The Walker’s Excelsior Mark IV instrument was designed for smaller vessels, such as yachts, launches and fishing vessels. Its exact date of manufacture cannot be determined but this design was manufactured in the first half of the 20th century. These mechanical logs have now been superseded by electronic equipment such as GPS navigation instruments.This instrument was made by a significant nautical instrument manufacturer and demonstrates the innovation needed at the time for improved navigation and safety at sea.Timber Box containing an instrument for measuring speed and distance. There is a brass, cased log with a white enamel dial. It also includes a towing cord and cylindrical rotator. The box has paper labelling on the front and also the inside of the lid. The label on the inside of the lid has instructions for use. Although the lid is hinged it has broken off and is separate. The hinges remain attached.Enamel Dial: Walkers Patent Excelsior Yacht Logmaritime, maritime history, tool, navigational tool, navigational instrument, navigation, sailing, walkers, maritime technology, walker & son