Archive for October, 2010

History Of Diving Helmets

October 29th, 2010

Copper Divers Helmet

The diving helmet which is worn by professional divers is incredibly adaptable for use in extreme circumstances. The diver’s helmet completely secures the head of the diver and allows for extensive voice communication with the operation team above water, and even with other divers. If anything were to occur to the diver when below water, such as being knocked unconscious, then the diving helmet will continue to pump air to the diver until he reawakens. This is very different from standard scuba gear which has to be knowingly held in the mouth. So if a scuba diver becomes unconscious, he or she will most likely drown due to the oxygen connection being cut off.

In the beginning, deep sea diving helmets were available with two to four bolts. The Kirby Morgan Superlite-17 designed in 1975 is a very noteworthy commercial diving helmet that is built with a fiberglass shell and chrome-plated brass fittings.These became the standard for modern commercial diving operations. The diving helmet can be attributed to Augustus Siebe, who is considered to be the father of diving. Siebe was a German born inventor from the 19th century who when living in England created a diving helmet. His version of the helmet had a watertight seal and an air-containing rubber suit. This was connected via an air pump on land and became the first useful application of the diving helmet and suit. The modern day diving suits used today are more reflective of the closed diving suit that Siebe Gorman & Co developed. Unlike earlier diving helmets, Siebe’s was sealed to the diving suit making it perfectly air tight. An enormous feat indeed. This proved to be a safer way for undersea exploration and helped to revolutionize the 1830s way of undersea exploration. Though, Alexander McKee stated that Siebe was merely the leading manufacturer of the designs made by brothers John and Charles Deane.

In the 1960′s, the commercial diver Joe Savoie invented the neck dam that made it possible for a new series of lighter weighted helmets to come about. Such types of lightweight helmets include the Superlight series. However, because he only wanted to improve the safety of divers, Savoie did not pursue a patent for his innovations.

The next step in the evolution of the diving helmet is the full face diving mask. This covered the entire face of the diver, and was held in place by way of adjustable straps. Indeed, the diving helmet came a long way since its invention to become the amazing piece of nautical equipment it is now.

The use of the diving helmet is not restricted to undersea adventures, however. Due to the air tight nature of the diving helmet, diving helmets were even used during the first world war to protect the British Army from the horrors of the notorious mustard gas that took the lives of many.

Now these classic copper diving helmet designs are used to adorn public museums and private nautical artifact collections around the world.

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History Of The Sextant

October 27th, 2010

Brass Sextant Paperweight

The sextant is a very important item for the navigator. However, like everything else on this planet, it had to evolve. The very beginnings of the sextant were a bit more unrefined and couldn’t quit hit the nail on the head. While modern day brass sextants are outclassed by the global positioning system, which many navigators criticize for it’s many faults.

The need for a navigational tool in the nautical realm arose as a way for exploration to take place on the treacherous uncharted seas. In order to use a sextant, a few things had to be done first. For instance, an almanac had to exist that included the location of celestial objects and bodies in relation to our planet at every single hour of every single day for many years. Furthermore, a device capable of measuring time to a precise point must be utilized. This is called a chronometer. Cartographers were necessary to plotting and charting maps so that longitude and latitude could be found and marked by the observer. A simple mathematical formula to transform the relation of the celestial body and the horizon with the navigators position would also be needed. With these things in place the sextant would be the final key in locating an accurate position of one’s self on the globe.

However, long before the invention of the sextant, navigators had to rely on Polaris to find their way back to their home port. The Arabs were very good at doing this, and used a device known as a Kamal to their advantage. The Kamal relied on a short rope and an object that sighted Polaris at the top and the horizon at the bottom. A knot was tied at the exact location of which he could align the two. When returning from a voyage back home the navigator would adjust his sailing in order to bring Polaris into the same position he had when he left port.

In the 10th century Arabs gave Europe two very important astronomical devices that would lead to the sextant – the astrolabe and the quadrant. The quadrant was especially useful to the Portuguese explorers. Explorers such as Columbus would mark off the points of altitude witnessed of Polaris similar to the Arab way of tying knots in the Kamal. This would be done in ports that the sailors wished to return to, and would eventually the alturas would become published so other sailors could find their way around the coasts of Europe and Africa.

The astrolabe was a remarkable device for use on sea as it could retain its position amongst the ever changing harsh conditions at sea. It was used for more than 200 years because of this. The astrolabe used a circular scale, and rotatable alidade with sighting pinnules. When held at eye level a celestial object could be viewed through the pinnules and the altitude read from the point of crossing by the alidade on the scale.

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History Of The Ship Wheel

October 25th, 2010

Wooden Ship Wheel

The ship’s wheel was predated by the use of the whip staff, which proved very insufficient. The ship’s wheel actually did not come about until very late in the development of the ship itself, until then the lackluster whip staff sufficed. The invention of the ship’s wheel is credited to the British Royal Navy, even though there has been no sufficient evidence to support this statement. It was believed to have been created by the workers in the ship docks and the artisans and not commissioned by the central government itself. The National Maritime Museum at Greenwich provides much back story on the history of the ships wheel.

The first ship wheels are thought to have been implemented around 1703, as seen in photographs of models from that period of time. However, this date is highly uncertain as there is not enough evidence short of a singular model ship that shows a fully developed wheel. Even if the ship’s wheel were invented then, it still may have taken some time for it to become commonplace in the use of ships. For instance, there is evidence that the Russel, an 80-gun ship started in 1707 was to be fitted with a whip staff. While in 1711, the 90-gun ship Ossory shows a design of a ship wheel in the proper place. While the 50-gun Gloucester of the same date used a whip staff. This evidence suggests that the ship wheel were probably truly invented closer to 1710 rather than circa 1702-03. By 1715, the ship’s wheel became the new standard for ships.

Early ship wheels were placed behind the mizzen mast, and above the tiller’s end, obstructing the helmsman’s view quite profoundly. Originally, the ship wheel was placed in front of a barrel of cylinder shape. It was to be operated by two men in heavy storm conditions, although the small amount of space caused them to get in the way of each other. Around 1740, many ships included two wheels. This allowed four men to be capable of steering if need be.

Early wheels suffered the problem of not having equal amounts of slack and tightening on both ends of the tiller rope. When the rope became hauled to one side, the angle of the center line of the ship became altered. This caused the rope to either become too tight or too slack. This flaw of design was not improved on for about 70 years until Pollard, Master Boat builder at Portsmouth Dockyard, introduced a new system. Pollard’s system was comprised of “sweeps and rowles” that were tested under Captain Bentinck in 1771. Pollard’s system was a success and became used as the standard by 1775.

The ship’s wheel is shrouded in many mysterious and discrepancies. While no one knows who invented the ship wheel at exactly what point in time, there is a general idea. It is one of the biggest steps taken in nautical navigating and helped to improve the way we view ships in the modern era.

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History Of The Spyglass

October 22nd, 2010

Nautical Spyglass

The spyglass was an important instrument for nautical use when the telescope was first invented. In 1608, three people are known for claiming credit to developing the first telescopes. However, it was Jacob Metius from the Netherlands who had produced a ‘spyglass’. Metius’s spyglass used an objective lens measuring 15 mm in diameter on one end and used a double concave eyepiece lens at the other. This gave his spyglass a magnification of about 3x. Thomas Harriott used one of these spyglass inventions of Metius to stare at the moon, and made remarkable drawings at the time that depicted many of the moon’s features.

Not long after Metius’s invention was used to peruse the land markings of our very own moon did Galileo begin to take interest in the telescope concept. He devised his own improved telescope that measure thirty-eight inches in length. After which he consistently improved upon the design using larger objective lenses, longer tubes, and stands to keep the telescope stable.

Johannes Kepler was the next to improve upon the spyglass originated by Metius, and improved upon by Galileo. Kepler decided it would be wise to thin out the objective lens, and make the eyepiece convex. He figured that these renovations would give the telescope a larger area of vision without suffering from the “fuzziness” that plauged Galileo’s own take on the spyglass. While Kepler himself never did get to build his design, it would be created by many others.

Even though Kepler sought to improve upon Galileo’s design, his own suffered from a crippling flaw. This was because his idea to input a thinner objective lens into his design made it so incoming light was bent less. This meant that the eyepiece would have to be further away than it was – an fl of about 100 feet to be exact. This length was very impractical and therefore they were not of much use.

While Metius’s spyglass and Galileo’s and Kepler’s contributions to its advancement were enormous leaps and bounds in technology, all of these early telescopes were pluaged with problems. The problem being a harsh “chromatic aberration”. What this meant was that white light being comprised of different colors at differing frequencies became bent by the lenses at different angles creating a “rainbow of colors around the image”. The result of which made Galileo’s telescopes’ suffer from such harsh fuzziness.

It wasn’t until the 1700s that it was discovered that different types of glass (as well as different shapes) had varying effects on bending light. Chester Hall, created a concave lens out of flint glass, and a convex lens from crown glass that when combined made no chromatic aberration. John Dollard improved even more so on this by actually cementing the lenses together, abolishing the nasty spherical aberration. However, the problem of creating a larger objective lens that did not suffer from bubbles was still at hand.

Despite the many flaws of early brass spyglasses and telescopes, they were still very essential to the way the world would shift in the 17th and 18th centuries. The improvements in technology made these devices capable of exploring more deeply into outer space as well as our own world.

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History Of The Telescope

October 20th, 2010

Brass Telescope With Stand

The invention of the telescope was certainly one that impacted the exploits of nautical travel in immeasurable ways. By understanding the location of the planet in relation with celestial objects far up above, sailors could improve their methods of navigating to be more precise. Indeed the nautical telescope helped to advance the improvements of nautical navigating as well as the world itself.

The telescope was invented in the Netherlands in 1608. The inventor of which is split between three different people who have all be credited with inventing the telescope. These people are: Hans Lippershey, Sacharias Jansen, and Jacob Metius. Hans is believed to have made the designs for the first working telescope, where on October 2, 1608 he made a patent for “seeing things far away as if they were nearby.” His patent just beat out Jacob Metius’s by only a mere couple of weeks. However, because of the claim by other individuals to have invented this device, Hans was not given his patent. Though, he was paid off for his design by the Dutch government. While these two may have been more public with their designs and patents for the telescope, Sacharias Jansen is widely thought to have preceded both inventors in his own design.

Convex and concave lens telescopes were the first of the Dutch telescopes constructed. They were made in such a way that the image was not inverted, and he original design by Hans only allowed for 3 times magnification. Not long after the invention, the telescope became made in high numbers all around Europe, and for good reason.

Galileo heard of this device that could make things far away seem as if they were near when in Venice June of the following year. Galileo’s interest in the telescope prompted a better design, as the inventor claimed to have fixed the construction flaw in the original design. He then made his own telescope with a convex lens on one end of a tube and a concave lens on the other. Shortly after, Galileo took his improved telescope design to Venice to introduce to the public. It is for this reason that many credit Galileo with the invention of the telescope, although he was just responsible for greatly improving the design.

Galileo began making even more powerful telescopes after this, greatly contributing to nautical navigators ease of sailing. The first telescope he created could only magnify 3 times, but he eventually produced a telescope capable of magnifying up to thirty-three diameters! This powerful adaption of the telescope helped him to see the orbiting satellites around Jupiter and the spots of the sun.

Later, telescopes were made of a variety of materials, including the popular brass telescope for nautical purposes.  Thanks to Lippershey and Galileo’s improvements on the telescope, space became more widely looked into, as well as the reaching corners of the seas by sailors and navigators. The nautical telescope needed not be as powerful as the lenses of the space reaching telescopes, but only to serve the purpose of looking far into the distance of the horizon.

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How To Calibrate A Sextant

October 18th, 2010

Brass Sextant Pen Holder

The sextant is a fairly complicated device. It relies on the use of a telescope for which one uses to spot the horizon and superimpose a celestial body onto it to determine one’s location. This is done by way of two opposing mirrors, one of which is attached to a moving scale that allows the light from a celestial object to be reflected onto the image of the horizon. However, if the sextant is not properly calibrated then the location the navigator perceives will be incorrect. This can be a very deadly fault, especially when at sea and without any other means of calculating location. This is why it is important to have the sextant that is intended for repeated use calibrated as much as needed.

Calibration of the sextant should be done at a facility that specializes in such. For instance, a United States Air Force aircraft bubble sextant (very different from a nautical sextant) should only be calibrated in a proper military-maintenance facility. This is done by propping the sextant on a calibration device, timing the mechanism’s average, and setting the elevation wheel to angles of 0, 30, 45, and 60 to check the HS reading. This will then have to be examined against preset marks to determine the correct calibration of the sextant.

Furthermore, you can calibrate a sextant by setting it on a table a certain distance from a wall and checking its elevation as opposed to pre-measured marks on the opposing wall. For example, if the sextant is about 5 feet away from the wall, then marking five feet higher than the height of the sextant’s eyepiece should show an elevation of 45 degrees. An improper reading will be considered the index error, and should be taken into account accordingly.

When using the marine sextant, calibration can be done by positioning the alidade to the 0 degree mark. Next, you will locate the horizon through the eyepiece. The image in the mirror should be aligned with the horizon. If not, then you will need to use the adjustment screws to position the mirror so that the image is calibrated correctly. You will know proper calibration when the two images are perfectly aligned with one another.

It is important that the sextant is calibrated before each use in order to make sure that the location you are getting is as accurate as possible. You must also take into account errors that may occur due to certain conditions. Calibrating the sextant will mean the difference between accurately knowing where you stand, and being totally lost. Luckily with the advent of a global positioning satellite, those who have a hard time calibrating a sextant, will be able to utilize GPS to their advantage. Though, GPS is extremely unreliable for its limited power source and constant loss of satellite reception.

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How To Use A Compass

October 15th, 2010

Brass Gimbal Compasses

In today’s world of GPS systems many people forget just how important a compass can be in a jam. For instance, if you are lost in the woods, your GPS could easily lose signal or simply die on you, leaving you without a clue in the world. The compass, on the other hand, will never die on you. This is because compasses are designed to follow magnetic north, and use the Earth’s magnetic field as its main source of power. As long as the Earth continues to put out a magnetic resonance, no matter how weak, then your brass compass (or any other kind of compass) will continue to work.

Using a compass is easier than you would think. It may seem difficult by all of the markings and numbers that litter the face of the compass, but its not too bad. The compass we will discuss will be the mountaineering compass, also known as the orienteering compass. To start, you should note that the red arrow of the compass is nearly always the arrow that points due north. The opposite arrow will either be black or white, depending on the compass. In order to gauge this fully, stand in the direction of the sun around noon. Your compass should point toward you, and not toward the sun. This is because the sun is in the general direction of the south around 12PM. Note that if you are south of the equator then your readings will be opposite.

Your compass will have the markings N, E, S, W for North, East, South, and West. In between each of these directions will be numbers that go to 360. These numbers represent the degrees of a complete circle. The lines that run through the face of the compass are called orientating lines, while the red lined arrow is called the orientating arrow. Outside of the compass you will find the direction of travel arrow. This is where your red needle should be pointing to in order to travel in the right direction.

Once you have that down, reading a compass will be easy. The first thing you must do is to hold your hands as steady as possible, with the compass close to your belly and the red needle pointing directly in front of you. You will see that the red needle is pointing toward N. Slowly rotate your entire body until the red needle is pointing to the E symbol. Now you’re going east, right? Wrong! Don’t make the mistake of thinking that just because you moved your body and the needle appears to be pointing east that it is. Remember, the red needle will always point north! The way that you get it to point to your intended direction is simple, however. Once you have the needle facing the E, begin rotating the compass housing (sometimes called the bearing) until the red needle is again pointing at the N and is in the orientating arrow. This will line up west with the direction of travel arrow, and you now know how to change directions and use a compass.

Try out a stylish pocket compass for a convenient way to take this navigational tool with you anywhere you go!

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How To Use A Sextant

October 13th, 2010

Brass Sextants

Upon first glance at the sextant one may feel intimidated by its many accessories. And the truth is, you really shouldn’t be. The basic use of the sextant is fairly easy; however, it is the charting, locating, and plotting that is the hardest part of using a sextant properly. The sextant works to find your position relative to a celestial object, such as the sun, moon, or stars. The celestial object is positioned over the horizon by way of two mirrors on the sextant that allow the navigator to determine the latitude they are currently in. The sextant can even work properly while on a moving ship. This is because the sextant sees the horizon directly and as unmoving, while the celestial object is viewed through two opposing mirrors that take into account the motion of the sextant from the reflection.

The sextant’s scale is one sixth that of a complete circle, which gives it the name “sextant”. The sextant’s two mirrors work in conjunction with the telescope, scale, and filters to determine an extremely accurate location. The mirror through which the navigator sees the horizon is half silvered to allow for light to come through. The second mirror opposing the first is attached to a movable arm that glides along the scale. The arm is moved so that the second mirror positions a celestial object’s light into the first mirror to give the appearance that the object is directly on the horizon. The angle between the two superimposed objects can be told by the points on the scale. This is the basic way of how to use a sextant.

Navigating the seas with a sextant is a very tricky affair that involves a lot of recalculating and astronomical references. The way to find latitude is by measuring the angle between sun and horizon while the sun sits at it’s highest point. The sun will be in the proper position at noon. From there you will have to reference a table compiled by astronomers that reveals where the sun should be at that particular time on that particular day. Due to the Earth’s steady motion, navigators can deduce that for every hour the sun will move 15 degrees. To measure this accurately and effectively navigators make use of a chronometer. A chronometer is basically an extremely accurate clock.

Using the sextant for celestial navigation as it was intended is a bit tougher. Celestial navigation measures angles in the sky in relation to the horizon in order to find the navigators global positioning. The position on Earth where the celestial object is aligned is known as the sub point, the location of which is found by referring to tables.

The measured angle of the celestial object and the horizon is directly correlated to the celestial object’s sub point and the navigators position. The measurement of this correlation defines a circle known as the celestial line of position (LOP). Of which the location and size is discovered by way of mathematical equations.

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How To Use A Telescope

October 11th, 2010