Showing posts with label Brass compass. Show all posts
Showing posts with label Brass compass. Show all posts

Monday, March 31, 2014

Wooden Ship wheel

Ship's wheel



ship's wheel is used to change its course. Together with the rest of the steering mechanism it forms part of the helm. It is typically connected to a mechanical, electric servo, or hydraulic system. In some modern ships the wheel is replaced with a simple toggle that remotely controls an electro-mechanical or electro-hydraulic drive for the rudder, with a rudder position indicator presenting feedback to the helmsman.
Helmsmen on older ships used a tiller (a horizontal bar fitted directly to the top of the rudder post) or a whipstaff (a vertical stick acting on a tiller).
Early ships' wheels (c. 1700) were operated to correspond to the motion                                          of The design of ships' wheels probably influenced that of the modern steering wheel.
the tiller, with a clockwise motion (corresponding to a right tiller motion) turning the rudder and thus the ship to the left. Eventually the control direction of the wheel was reversed to make it more consistent with the action of a motor vehicle's steering wheel.
A traditional ship's wheel is composed of eight cylindrical wooden spokes (though sometimes as few as six or as many as ten) shaped like balustersand all joined at a central wooden hub or nave (sometimes covered with a brass nave plate) which housed the axle. The square hole at the centre of the hub through which the axle ran is called a drive square and was often lined with a brass plate (and therefore called a brass boss, though this term was used more often to refer to a brass hub and nave plate) which was frequently etched with the name of the wheel's manufacturer. The outer rim is composed of four sections each made up of stacks of three felloes, the facing felloe, the middle felloe, and the after felloe. Because each group of three felloes at one time made up a quarter of the distance around the rim, the entire outer wooden wheel was sometimes called the quadrant. Each spoke ran through the middle felloe creating a series of handles on the outside of the wheel's rim. One of these handles/ spokes was frequently given extra grooves at its tip which could be felt by a helmsman steering in the dark and used by him to determine the exact position of the rudder—this was theking spoke and when it pointed straight upward the rudder was dead straight. The wood used in construction of this type of wheel was most often eitherteak or mahogany.
The steering gear of earlier ships sometimes consisted of a double wheel where each wheel was connected to the other with a wooden spindle that ran through a barrel or drum. The spindle was held up by two pedestals that rested on a wooden platform, often no more than a grate. A tiller rope or chain (sometimes called a steering rope or chain) ran around the barrel in five or six loops and then down through two tiller rope slots at the top of the platform before connecting to two sheaves just below deck (one on either side of the ship's wheel) and thence out to a pair of pulleys before coming back together at the tiller and therefore the ships rudder. Movement of the wheels (which were connected and moved simultaneously) caused the tiller rope to wind in one of two directions and shifted the tiller left or right. In a typical and intuitive arrangement, a helmsman turning the wheel counterclockwise would cause the tiller to move to starboard and therefore the rudder to swing to port causing the vessel to also turn to port.

Wednesday, March 19, 2014

Nautical Compass - Maximus International - www.replicartz.com

Compass

compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the Earth. The frame of reference defines the four cardinal directions (or points) – north, south, east, and west. Intermediate directions are also defined. Usually, a diagram called a compass rose, which shows the directions (with their names usually abbreviated to initials), is marked on the compass. When the compass is in use, the rose is aligned with the real directions in the frame of reference, so, for example, the "N" mark on the rose really points to the north. Frequently, in addition to the rose or sometimes instead of it, angle markings in degrees are shown on
the compass. North corresponds to zero degrees, and the angles increase clockwise, so east is 90 degrees, south is 180, and west is 270. These numbers allow the compass to showazimuths or bearings, which are commonly stated in this notation.
The magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty (since about 206 BC). The compass was used in Song Dynasty China by the military for navigational orienteering by 1040-1044, and was used for maritime navigation by 1111 to 1117.The use of a compass is,This was supplanted in the early 20th century by the liquid-filled magnetic compass.
recorded in Western Europe between 1187 and 1202, and in Persia in 1232.The dry compass was invented in Europe around 1300.

Types of compasses




There are two widely used and radically different types of compass. The magnetic compass contains a magnet earth's magnetic field and aligns itself to point to the magnetic poles.[14] Simple compasses of this type show directions in a frame of reference in which the directions of the magnetic poles are due north and south. These directions are called magnetic north and magnetic south. The gyro compass (sometimes spelled with a hyphen, or as one word) contains a rapidly spinning wheel whose rotation interacts dynamically with the rotation of the earth so as to make the wheel precess, losing energy to friction until its axis of rotation is parallel with the earth's. The wheel's axis therefore points to the earth's rotational poles, and a frame of reference is used in which the directions of the rotational poles are due north and south. These directions are called true north andtrue south, respectively. The astrocompass works by observing the direction of stars and other celestial bodies.                                                                           
There are other devices which are not conventionally called compasses but which do allow the true cardinal directions to be determined. Some GPSreceivers have two or three antennas, fixed some distance apart to the structure of a vehicle, usually an aircraft or ship. The exact latitudes and longitudes of the antennas can be determined simultaneously, which allows the directions of the cardinal points to be calculated relative to the heading of the aircraft (the direction in which its nose is pointing), rather than to its direction of movement, which will be different if there is a crosswind. They are said to work "like a compass", or "as a compass".
Even a GPS device or similar can be used as compass, since if the receiver is being moved, even at walking pace, it can follow the change of its position, and hence determine the compass bearing of its direction of movement, and hence the directions of the cardinal points relative to its direction of movement. A much older example was the Chinese south-pointing chariot, which worked like a compass by directional dead reckoning. It was initialized by hand, possibly using astronomical observations e.g. of the Pole Star, and thenceforth counteracted every turn that was made to keep its pointer aiming in the desired direction, usually to the south. Watches and sundials can also be used to find compass directions. See their articles for details.
A recent development is the electronic compass which detects the direction without potentially fallible moving parts. This may use a fibre optic gyrocompass or a magnetometer. The magnetometer frequently appears as an optional subsystem built into hand-held GPS receivers and mobile phones. However, magnetic compasses remain popular, especially in remote areas, as they are relatively inexpensive, durable, and require no power supply.

Magnetic compass
The magnetic compass consists of a magnetized pointer (usually marked on the North end) free to align itself with Earth's magnetic field. A compass is any magnetically sensitive device capable of indicating the direction of the magnetic north of a planet's magnetosphere. The face of the compass generally highlights the cardinal points of north, south, east and west. Often, compasses are built as a stand alone sealed instrument with a magnetized bar or needle turning freely upon a pivot, or moving in a fluid, thus able to point in a northerly and southerly direction.
The compass greatly improved the safety and efficiency of travel,
especially ocean travel. A compass can be used to calculate heading, used with a sextant to calculate latitude, and with a marine chronometer to calculate longitude. It thus provides a much improved navigational capability that has only been recently supplanted by modern devices such as the Global Positioning System(GPS).








Friday, March 7, 2014

Sextant history & use - Nautical sextant manufacturer

Sextant

Nautical Sextant Manufacturer
Nautical sextant manufacturer
sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the object's altitude. Using this measurement is known as sighting the object, shooting the object, or taking a sight and it is an essential part of celestial navigation. The angle, and the time when it was measured, can be used to calculate a position line on a nautical or aeronautical chart. Common uses of the sextant include sighting the sun at solar noon and sighting Polaris at night (in the Northern Hemisphere), to find one's latitude. Sighting the height of a landmark can give a measure of distance off and, held horizontally, a sextant can measure angles between objects for a position [1] A sextant can also be used to measure the lunar distance between the moon and another celestial object (e.g., star, planet) in order to determine Greenwich time which is important because it can then be used to determine the longitude on a chart.The scale of a sextant has a length of  of a turn (60°); hence the sextant's name (sextāns, -antis is the Latin word for "one sixth"). An octant is a similar device with a shorter scale ( turn, or 45°), where as a quintant ( turn, or 72°) and a quadrant (¼ turn, or 90°) have longer scales.
Sir Isaac Newton (1643–1727) invented the principle of the doubly reflecting navigation instrument (a reflecting quadrant—see Octant (instrument)), but never published it. Two men independently developed the octant around 1730: John Hadley (1682–1744), an English mathematician, and Thomas Godfrey (1704–1749), a glazier in Philadelphia. John Bird made the first sextant in 1757. The octant and later the sextant, replaced the Davis quadrantas the main instrument for navigation.


Advantages

Nautical sextant manufacturer
Like the Davis quadrant (also called backstaff), the sextant allows celestial objects to be measured relative to the horizon, rather than relative to the instrument. This allows excellent precision. However, unlike the backstaff, the sextant allows direct observations of stars. This permits the use of the sextant at night when a backstaff is difficult to use. For solar observations, filters allow direct observation of the sun.
Since the measurement is relative to the horizon, the measuring pointer is a beam of light that reaches to the horizon. The measurement is thus limited by the angular accuracy of the instrument and not the sine error of the
length of an alidade, as it is in a mariner's astrolabe or similar older instrument.
A sextant does not require a completely steady aim, because it measures a relative angle. For example, when a sextant is used on a moving ship, the image of both horizon and celestial object will move around in the field of view. However, the relative position of the two images will remain steady, and as long as the user can determine when the celestial object touches the horizon the accuracy of the measurement will remain high compared to the magnitude of the movement.
Nautical sextant manufacturer
The sextant is not dependent upon electricity (unlike many forms of modern navigation) or anything human-controlled (like GPS satellites). For these reasons, it is considered an eminently practical back-up navigation tool for ships.

Monday, January 27, 2014

Brunton compass

Brunton compass, properly known as the Brunton Pocket Transit, is a type of precision compass made by Brunton, Inc. of Riverton,Wyoming. The instrument was patented in 1894 by a Canadian-born Colorado geologist named David W. Brunton. Unlike most modern compasses, the Brunton Pocket Transit utilizes magnetic induction damping rather than fluid to damp needle oscillation. Although Brunton Inc. makes many other types of magnetic compasses, the Brunton Pocket Transit is a specialized instrument used widely by those needing to make accurate degree and angle measurements in the field. These people are primarily geologists, but archaeologists,environmental engineers, and surveyors also make use of the Brunton's capabilities. The United States Army has adopted the Pocket Transit as the M2 Compass for use by crew-served artillery also in nautical.
The Pocket Transit may be adjusted for declination angle according to one's location on the Earth. It is used to get directional degree measurements (azimuth) through use of the Earth's magnetic field. Holding the compass at waist-height, the user looks down into the mirror and lines up the target, needle, and guide line that is on the mirror. Once all three are lined up and the compass is level, the reading for that azimuth can be made. Arguably the most frequent use for the Brunton in the field is the calculation of the strike and dip ofgeological features (faults, contacts, foliation, sedimentary strata, etc.). If next to the feature, the strike is measured by leveling (with thebull's eye level) the compass along the plane being measured. Dip is taken by laying the side of the compass perpendicular to the strike measurement and rotating horizontal level until the bubble is stable and the reading has been made. If properly used and if field conditions allow, additional features of the compass allow users to measure such geological attributes from a distance.

And here at Maximus Inernational we are Manufacturer of compasses and other nautical maritime items based in india.

Saturday, January 25, 2014

Historical reenactment is a scripted educational or entertainment activity in which participants follow a prearranged plan to recreate aspects of a historical event or period—often a military engagement or display. This may be as narrow as a specific moment from a battle, such as the reenactment of Pickett's Charge presented during the Great Reunion of 1913, or as broad as an entire period, such as Regency reenactment or The 1920s Berlin Project.

Historical reenactment through the ages


Activities related to "reenactment" have a long history. The Romans staged recreations of famous battles within their amphitheaters as a form of public spectacle. In the Middle Agestournaments often reenacted historical themes from Ancient Rome or elsewhere. In the nineteenth century, reenactments were popular in a number of countries, e.g. the Eglinton Tournament of 1839 in Britain. During the early twentieth century they were popular in Russia with re-enactments of the Siege of Sevastopol (1854–1855) (1906), the Battle of Borodino (1812) in St Petersburg and the Taking of Azov (1696) in Voronezh in 1918. In 1920, there was a reenactment of the 1917Storming of the Winter Palace on the third anniversary of the event. This reenactment inspired the scenes in Sergei Eisenstein's filmOctober: Ten Days That Shook the World.
Likewise, mass pageants were used to commemorate civic events like the 150th anniversary of the founding of St Louis, held in 1914.[1] Particularly during and since the centennial of the American Civil War in the United States beginning in 1961, reenactments of Civil War battles has attracted many reenactors, who are some of the most dedicated.
We at maximus international manufacture a huge range of such items.











Wednesday, January 22, 2014

Maximus International manufacturer suppliers & exporters.













About Us
Maximus International Specialists in Nautical Accessories, the Quality of the designed aesthetic pieces we procure, and provide, enhance and rejuvenating the space they hold. Captivating and mood inspiring, your home or office will always have a eye catching work of art to impress even the most objective of visitors. We put many years of our importing and business experience to offer you a fascinating range of nautical items, gifts and decor, fine replicas of antique brass telescopes, compasses and sextants, precisely working clocks, spot & search lights, lamps, cargo lanterns,  armour helmets, greek armoury, roman armoury, medieval armoury, ancient armoury and more. These unique and attractive antiques bring a historical elegance to any room or space and is very fashionable. Items like nautical clocks, captain bells, etc. will make great desk or home decoration, and are excellent as gifts for like minded enthusiasts.

At Maximus International we leave no stone unturned to fill the needs of our clients. Our aim is to help both local and overseas customers do their antique browsing and shopping from the comfort of their own home. A user-friendly e-commerce interface, highly experienced manufacturing vendors and agile warehouse systems are just some of the features we have roped in for the convenience of our customers.We always strive to deliver best customer service such that you wouldn’t resist visiting us again sooner All our replica products are reasonably priced. We are passionate about our business and therefore passionate about helping you find that treasured antique that will compliment your home decoration or add to the discerning collectors unique range. Contact us to discuss any of our online products.
We can also develop any new product which is part of your dream and imagination provided you give us clues about it with the help of ideas, sketches or photographs. The products are manufactured with utmost care to infuse them with the best strength and appearance. The fantastic products are then packed in the most trendy and safest way so that our dear customers can use and cherish them for whole life. Apart from these, resolving the doubts and difficulties is also the parallel objective of our skilled workforce. We are a prominent company in the industry sector. Your dreams braid with our dreams!