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