A compass is an instrument used for navigation and orientation that shows direction relative to the geographic cardinal directions. A diagram called a compass rose shows the directions north, south and west on the compass face as abbreviated initials; when the compass is used, the rose. Compasses display markings for angles in degrees in addition to the rose. North corresponds to 0°, the angles increase clockwise, so east is 90° degrees, south is 180°, west is 270°; these numbers allow the compass to show magnetic North azimuths or true North azimuths or bearings, which are stated in this notation. If magnetic declination between the magnetic North and true North at latitude angle and longitude angle is known direction of magnetic North gives direction of true North. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty, adopted for navigation by the Song Dynasty Chinese during the 11th century; the first usage of a compass recorded in Western Europe and the Islamic world occurred around 1190.
The magnetic compass is the most familiar compass type. It functions as a pointer to "magnetic north", the local magnetic meridian, because the magnetized needle at its heart aligns itself with the horizontal component of the Earth's magnetic field; the magnetic field exerts a torque on the needle, pulling the North end or pole of the needle toward the Earth's North magnetic pole, pulling the other toward the Earth's South magnetic pole. The needle is mounted on a low-friction pivot point, in better compasses a jewel bearing, so it can turn easily; when the compass is held level, the needle turns until, after a few seconds to allow oscillations to die out, it settles into its equilibrium orientation. In navigation, directions on maps are expressed with reference to geographical or true north, the direction toward the Geographical North Pole, the rotation axis of the Earth. Depending on where the compass is located on the surface of the Earth the angle between true north and magnetic north, called magnetic declination can vary with geographic location.
The local magnetic declination is given on most maps, to allow the map to be oriented with a compass parallel to true north. The location of the Earth's magnetic poles change with time, referred to as geomagnetic secular variation; the effect of this means. Some magnetic compasses include means to manually compensate for the magnetic declination, so that the compass shows true directions. There are other ways to find north than the use of magnetism, from a navigational point of view a total of seven possible ways exist. Two sensors that utilize two of the remaining six principles are also called compasses, i.e. gyrocompass and GPS-compass. A gyrocompass is similar to a gyroscope, it is a non-magnetic compass that finds true north by using an fast-spinning wheel and friction forces in order to exploit the rotation of the Earth. Gyrocompasses are used on ships, they have two main advantages over magnetic compasses: they find true north, i.e. the direction of Earth's rotational axis, as opposed to magnetic north, they are not affected by ferromagnetic metal in a ship's hull.
Large ships rely on a gyrocompass, using the magnetic compass only as a backup. Electronic fluxgate compasses are used on smaller vessels. However, magnetic compasses are still in use as they can be small, use simple reliable technology, are comparatively cheap, are easier to use than GPS, require no energy supply, unlike GPS, are not affected by objects, e.g. trees, that can block the reception of electronic signals. GPS receivers using two or more antennae mounted separately and blending the data with an inertial motion unit can now achieve 0.02° in heading accuracy and have startup times in seconds rather than hours for gyrocompass systems. The devices determine the positions of the antennae on the Earth, from which the cardinal directions can be calculated. Manufactured for maritime and aviation applications, they can detect pitch and roll of ships. Small, portable GPS receivers with only a single antenna can determine directions if they are being moved if only at walking pace. By determining its position on the Earth at times a few seconds apart, the device can calculate its speed and the true bearing of its direction of motion.
It is preferable to measure the direction in which a vehicle is moving, rather than its heading, i.e. the direction in which its nose is pointing. These directions may be different if there is tidal current. GPS compasses share the main advantages of gyrocompasses, they determine true North, as opposed to magnetic North, they are unaffected by perturbations of the Earth's magnetic field. Additionally, compared with gyrocompasses, they are much cheaper, they work better in polar regions, they are less prone to be affected by mechanical vibration, they can be initialized far more quickly. However, they depend on the functioning of, communication with, the GPS satellites, which might be disrupted by an electronic attack or by the effects of
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, space navigation, it is the term of art used for the specialized knowledge used by navigators to perform navigation tasks. All navigational techniques involve locating the navigator's position compared to known locations or patterns. Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and direction. In this sense, navigation includes pedestrian navigation. In the European medieval period, navigation was considered part of the set of seven mechanical arts, none of which were used for long voyages across open ocean. Polynesian navigation is the earliest form of open-ocean navigation, it was based on memory and observation recorded on scientific instruments like the Marshall Islands Stick Charts of Ocean Swells.
Early Pacific Polynesians used the motion of stars, the position of certain wildlife species, or the size of waves to find the path from one island to another. Maritime navigation using scientific instruments such as the mariner's astrolabe first occurred in the Mediterranean during the Middle Ages. Although land astrolabes were invented in the Hellenistic period and existed in classical antiquity and the Islamic Golden Age, the oldest record of a sea astrolabe is that of Majorcan astronomer Ramon Llull dating from 1295; the perfecting of this navigation instrument is attributed to Portuguese navigators during early Portuguese discoveries in the Age of Discovery. The earliest known description of how to make and use a sea astrolabe comes from Spanish cosmographer Martín Cortés de Albacar's Arte de Navegar published in 1551, based on the principle of the archipendulum used in constructing the Egyptian pyramids. Open-seas navigation using the astrolabe and the compass started during the Age of Discovery in the 15th century.
The Portuguese began systematically exploring the Atlantic coast of Africa from 1418, under the sponsorship of Prince Henry. In 1488 Bartolomeu Dias reached the Indian Ocean by this route. In 1492 the Spanish monarchs funded Christopher Columbus's expedition to sail west to reach the Indies by crossing the Atlantic, which resulted in the Discovery of the Americas. In 1498, a Portuguese expedition commanded by Vasco da Gama reached India by sailing around Africa, opening up direct trade with Asia. Soon, the Portuguese sailed further eastward, to the Spice Islands in 1512, landing in China one year later; the first circumnavigation of the earth was completed in 1522 with the Magellan-Elcano expedition, a Spanish voyage of discovery led by Portuguese explorer Ferdinand Magellan and completed by Spanish navigator Juan Sebastián Elcano after the former's death in the Philippines in 1521. The fleet of seven ships sailed from Sanlúcar de Barrameda in Southern Spain in 1519, crossed the Atlantic Ocean and after several stopovers rounded the southern tip of South America.
Some ships were lost, but the remaining fleet continued across the Pacific making a number of discoveries including Guam and the Philippines. By only two galleons were left from the original seven; the Victoria led by Elcano sailed across the Indian Ocean and north along the coast of Africa, to arrive in Spain in 1522, three years after its departure. The Trinidad sailed east from the Philippines, trying to find a maritime path back to the Americas, but was unsuccessful; the eastward route across the Pacific known as the tornaviaje was only discovered forty years when Spanish cosmographer Andrés de Urdaneta sailed from the Philippines, north to parallel 39°, hit the eastward Kuroshio Current which took its galleon across the Pacific. He arrived in Acapulco on October 8, 1565; the term stems from the 1530s, from Latin navigationem, from navigatus, pp. of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" and the root of agere "to drive". The latitude of a place on Earth is its angular distance north or south of the equator.
Latitude is expressed in degrees ranging from 0° at the Equator to 90° at the North and South poles. The latitude of the North Pole is 90° N, the latitude of the South Pole is 90° S. Mariners calculated latitude in the Northern Hemisphere by sighting the North Star Polaris with a sextant and using sight reduction tables to correct for height of eye and atmospheric refraction; the height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so. Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the prime meridian or Greenwich meridian. Longitude is expressed in degrees ranging from 0° at the Greenwich meridian to 180° east and west. Sydney, for example, has a longitude of about 151° east. New York City has a longitude of 74° west. For most of history, mariners struggled to determine longitude. Longitude can be calculated. Lacking that, one can use a sextant to take a lunar distance that, with a nautical almanac, can be used to calculate the time at zero longitude.
Reliable marine chronometers were unavailable until the late 18th century and not affordable until the 19th century. For about a hundred years, from about 1767 until about 1850, mariners lacking a chronometer used the method of lunar distances to determine Greenwich time to find their longitude. A mariner with a chronometer could check its reading using a lunar determination of Greenwich tim
Feces are the solid or semisolid remains of the food that could not be digested in the small intestine. Bacteria in the large intestine further break down the material. Feces contain a small amount of metabolic waste products such as bacterially altered bilirubin, the dead epithelial cells from the lining of the gut. Feces are discharged through cloaca during a process called defecation. Feces can be used as soil conditioner in agriculture, it can be burned and used as a fuel source or dried and used as a construction material. Some medicinal uses have been found. In the case of human feces, fecal transplants or fecal bacteriotherapy are in use. Urine and feces together are called excreta; the distinctive odor of feces is due to bacterial action. Gut flora produces compounds such as indole and thiols, as well as the inorganic gas hydrogen sulfide; these are the same compounds. Consumption of foods prepared with spices may result in the spices being undigested and adding to the odor of feces; the perceived bad odor of feces has been hypothesized to be a deterrent for humans, as consuming or touching it may result in sickness or infection.
Human perception of the odor may be contrasted by a non-human animal's perception of it. Feces are discharged through cloaca during a process called defecation; this process requires pressures that may reach 100 mm Hg in 450 mm Hg in penguins. The forces required to expel the feces are generated through muscular contractions and a build-up of gases inside the gut, prompting the sphincter to relieve the pressure on it and to release the feces. After an animal has digested eaten material, the remains of that material are discharged from its body as waste. Although it is lower in energy than the food from which it is derived, feces may retain a large amount of energy 50% of that of the original food; this means that of all food eaten, a significant amount of energy remains for the decomposers of ecosystems. Many organisms feed on feces, from bacteria to fungi to insects such as dung beetles, who can sense odors from long distances; some may specialize in feces. Feces serve not only as a basic food, but as a supplement to the usual diet of some animals.
This process is known as coprophagia, occurs in various animal species such as young elephants eating the feces of their mothers to gain essential gut flora, or by other animals such as dogs and monkeys. Feces and urine, which reflect ultraviolet light, are important to raptors such as kestrels, who can see the near ultraviolet and thus find their prey by their middens and territorial markers. Seeds may be found in feces. Animals who eat fruit are known as frugivores. An advantage for a plant in having fruit is that animals will eat the fruit and unknowingly disperse the seed in doing so; this mode of seed dispersal is successful, as seeds dispersed around the base of a plant are unlikely to succeed and are subject to heavy predation. Provided the seed can withstand the pathway through the digestive system, it is not only to be far away from the parent plant, but is provided with its own fertilizer. Organisms that subsist on dead organic matter or detritus are known as detritivores, play an important role in ecosystems by recycling organic matter back into a simpler form that plants and other autotrophs may absorb once again.
This cycling of matter is known as the biogeochemical cycle. To maintain nutrients in soil it is therefore important that feces return to the area from which they came, not always the case in human society where food may be transported from rural areas to urban populations and feces disposed of into a river or sea. Depending on the individual and the circumstances, human beings may defecate several times a day, every day, or once every two or three days; the extensive hardening that interrupts this routine for several days or more is called constipation. The appearance of human fecal matter varies according to health, it is semisolid, with a mucus coating. A combination of bile and bilirubin, which comes from dead red blood cells, gives feces the typical brown color. After the meconium, the first stool expelled, a newborn's feces contain only bile, which gives it a yellow-green color. Breast feeding babies expel soft, pale yellowish, not quite malodorous matter. At different times in their life, human beings will expel feces of different textures.
A stool that passes through the intestines will look greenish. The feces of animals are used as fertilizer. Dry animal dung is used as a fuel source in many countries around the world; some animal feces that of camel and cattle, are fuel sources when dried. Animals such as the giant panda and zebra possess gut bacteria capable of producing biofuel; that bacteria, called Brocadia anammoxidans, can create the rocket fuel hydrazine. A coprolite is classified as a trace fossil. In paleontology they give evidence about the diet of an animal, they were first described by William Buckland in 1829. Prior to this they were known as "fossil fir cones" and "bezoar stones", they serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms. Coprolites may range in size from a few millimetres to more than 60 centimetres. Palaeofeces are ancie
Hiking is the preferred term, in Canada and the United States, for a long, vigorous walk on trails, in the countryside, while the word walking is used for shorter urban walks. On the other hand, in the United Kingdom, the Republic of Ireland, the word "walking" is acceptable to describe all forms of walking, whether it is a walk in the park or backpacking in the Alps; the word hiking is often used in the UK, along with rambling and fell walking. The term bushwalking is endemic to Australia, having been adopted by the Sydney Bush Walkers club in 1927. In New Zealand a long, vigorous walk or hike is called tramping, it is a popular activity with numerous hiking organizations worldwide, studies suggest that all forms of walking have health benefits. In the United States, the Republic of Ireland, United Kingdom, hiking means walking outdoors on a trail, or off trail, for recreational purposes. A day hike refers to a hike. However, in the United Kingdom, the word walking is used, as well as rambling, while walking in mountainous areas is called hillwalking.
In Northern England, Including the Lake District and Yorkshire Dales, fellwalking describes hill or mountain walks, as fell is the common word for both features there. Hiking is sometimes referred to as such; this refers to difficult walking through dense forest, undergrowth, or bushes, where forward progress requires pushing vegetation aside. In extreme cases of bushwhacking, where the vegetation is so dense that human passage is impeded, a machete is used to clear a pathway; the Australian term bushwalking refers to both on and off-trail hiking. Common terms for hiking used by New Zealanders are walking or bushwalking. Trekking is the preferred word used to describe multi-day hiking in the mountainous regions of India, Nepal, North America, South America and the highlands of East Africa. Hiking a long-distance trail from end-to-end is referred to as trekking and as thru-hiking in some places. In North America, multi-day hikes with camping, are referred to as backpacking; the idea of taking a walk in the countryside for pleasure developed in the 18th century, arose because of changing attitudes to the landscape and nature associated with the Romantic movement.
In earlier times walking indicated poverty and was associated with vagrancy. Thomas West, an English priest, popularized the idea of walking for pleasure in his guide to the Lake District of 1778. In the introduction he wrote that he aimed to encourage the taste of visiting the lakes by furnishing the traveller with a Guide. To this end he included various'stations' or viewpoints around the lakes, from which tourists would be encouraged to enjoy the views in terms of their aesthetic qualities. Published in 1778 the book was a major success. Another famous early exponent of walking for pleasure, was the English poet William Wordsworth. In 1790 he embarked on an extended tour of France and Germany, a journey subsequently recorded in his long autobiographical poem The Prelude, his famous poem Tintern Abbey was inspired by a visit to the Wye Valley made during a walking tour of Wales in 1798 with his sister Dorothy Wordsworth. Wordsworth's friend Coleridge was another keen walker and in the autumn of 1799, he and Wordsworth undertook a three weeks tour of the Lake District.
John Keats, who belonged to the next generation of Romantic poets began, in June 1818, a walking tour of Scotland and the Lake District with his friend Charles Armitage Brown. More and more people undertook walking tours through the 19th century, of which the most famous is Robert Louis Stevenson's journey through the Cévennes in France with a donkey, recorded in his Travels with a Donkey. Stevenson published in 1876 his famous essay "Walking Tours"; the subgenre of travel writing produced many classics in the subsequent 20th century. An early American example of a book that describes an extended walking tour is naturalist John Muir's A Thousand Mile Walk to the Gulf, a posthumous published account of a long botanizing walk, undertaken in 1867. Due to industrialisation in England, people began to migrate to the cities where living standards were cramped and unsanitary, they would escape the confines of the city by rambling about in the countryside. However, the land in England around the urban areas of Manchester and Sheffield, was owned and trespass was illegal.
Rambling clubs soon sprang up in the north and began politically campaigning for the legal'right to roam'. One of the first such clubs, was'Sunday Tramps' founded by Leslie White in 1879; the first national grouping, the Federation of Rambling Clubs, was formed in London in 1905 and was patronized by the peerage. Access to Mountains bills, that would have legislated the public's'right to roam' across some private land, were periodically presented to Parliament from 1884 to 1932 without success. In 1932, the Rambler’s Right Movement organized a mass trespass on Kinder Scout in Derbyshire. Despite attempts on the part of the police to prevent the trespass from going ahead it was achieved due to massive publicity; however the Mountain Access Bill, passed in 1939 was opposed by many walkers' organizations, including The Ramblers, who felt that it did not
A whistle is an instrument which produces sound from a stream of gas, most air. It may be powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a large multi-piped church organ. Whistles have been around since early humans first carved out a gourd or branch and found they could make sound with it. In prehistoric Egypt, small shells were used as whistles. Many present day wind instruments are inheritors of these early whistles. With the rise of more mechanical power, other forms of whistles have been developed. One characteristic of a whistle is that it creates nearly pure, tone; the conversion of flow energy to sound comes from an interaction between a solid material and a fluid stream. The forces in some whistles are sufficient to set the solid material in motion. Classic examples are Aeolian tones that result in galloping power lines, or the Tacoma Narrows Bridge. Other examples are circular disks set into vibration. Depending on the geometry, there are two basic types of whistles: those that generate sound through oscillations of fluid mass flow, those that generate sound through oscillations of the force applied to the surrounding medium.
Whistles made of bone or wood have been used for thousands of years. Whistles were used by the Ancient Greeks to keep the stroke of galley slaves; the English used whistles during the Crusades to signal orders to archers. Boatswain pipes were used in the age of sail aboard naval vessels to issue commands and salute dignitaries. Joseph Hudson set up J Hudson & Co in Birmingham, UK in 1870. With his younger brother James, he designed the'Acme City' brass whistle; this became the first referee whistle used at association football matches during the 1878–79 Football Association Cup match between Nottingham Forest and Sheffield. Prior to the introduction of the whistle, handkerchiefs were used by the umpires to signal to the players. In 1883 he began experimenting with pea-whistle designs that could produce an intense sound that could grab attention from over a mile away, his invention was discovered by accident, when he accidentally dropped his violin and it shattered on the floor. Observing how the discordant sound of the breaking strings travelled, Hudson had the idea to put a pea in the whistle.
Prior to this, whistles were much quieter, were only thought of as musical instruments or toys for children. After observing the problems that local police were having with communicating with rattles, he realised that his whistle designs could be used as an effective aid to their work. Hudson demonstrated his whistle to Scotland Yard and was awarded his first contract in 1884. Both Ratchet rattles and whistles were used to call for back-up in areas where neighbourhood beats overlapped, following their success in London, the whistle was adopted by most police in the United Kingdom; this police whistle monopoly made Hudson the largest whistle manufacturer in the world, supplying police forces and other general services everywhere. His whistle is still used by many forces worldwide, his design, was improved as the'Acme Thunderer', the first pea whistle, which remains the most used whistle in the world. From the 1880s and 1890s, J. Hudson & Co began facing greater competition, as other whistle manufacturing companies were established, including W. Dowler & Sons, J. Barrall, R. A. Walton, H. A. Ward and A. De Courcy & Co.
In 1987, Ron Foxcroft released the Fox 40 pealess whistle, designed to replace the pea whistle and be more reliable. Human whistling unaided by any instrument can be used for musical recreation or as a whistled language for communication over distances too great for articulate speech, among many other purposes. Musical instruments include the tin whistle and the slide whistle. Since a whistle produces a loud sound that carries over a great distance, whistles are useful for signalling. On ships, the boatswain's call is used to alert members of the crew. A dog whistle can be used to train a dog for herding, or other occupations. Industrial plants use a steam whistle to signal shift changes or to give alarms of emergencies. A small-scaled steam whistle is found on a whistling kettle, to alert the user that the water is boiling. Storage tanks may be equipped with a whistle vent which sounds continually as the tank is being filled, they occur as accidental byproducts of fluid flow such as supersonic jets, cavity resonances, whistling telephone wires, idling circular saws.
Vessel flute Low whistle Liquid whistle Physics of whistles Firedamp whistle Whistler Rossby whistle Media related to whistles at Wikimedia Commons The dictionary definition of whistle at Wiktionary Chisholm, Hugh, ed.. "Whistle". Encyclopædia Britannica. 28. Cambridge University Press. Pp. 595–596. Whistle
A space blanket is an low-weight, low-bulk blanket made of heat-reflective thin plastic sheeting. They are used on the exterior surfaces of spacecraft for thermal control, as well as by people, their design reduces the heat loss in a person's body, which would otherwise occur due to thermal radiation, water evaporation, or convection. Their compact size before unfurling and light weight makes them ideal when space or weight are at a premium, they may be included in first aid kits and in camping equipment. Lost campers and hikers have an additional possible benefit: the metallic surface appearance flashes in the sun, allowing use as an improvised distress beacon for searchers and as a method of signalling over long distances to other people on the same route as the person who owns the blanket. First developed by NASA's Marshall Space Flight Center in 1964 for the US space program, the material consists of a thin sheet of plastic, coated with a metallic reflecting agent, making it metallized polyethylene terephthalate gold or silver in colour, which reflects up to 97% of radiated heat.
For use in space, polyimide substrate is employed due to its resistance to the hostile space environment, large temperature range, low outgassing and resistance to ultraviolet radiation. Aluminized kapton, with foil thickness of 50 and 125 µm, was used e.g. on the Apollo Lunar Module. The polyimide gives the foils their distinctive amber-gold color. Space blankets are made by vacuum-depositing a precise amount of pure aluminum vapor onto a thin, durable film substrate. In their principal usage, space blankets are included in many emergency, first aid, survival kits because they are waterproof and windproof. That, along with their low weight and ability to pack into a small space, has made them popular among outdoor enthusiasts and emergency workers. Space blankets are given to marathoners and other endurance athletes at the end of races, or while waiting before races if the weather is chilly; the material may be used in conjunction with conductive insulation material and may be formed into a bag for use as a bivouac sack.
In first aid, the blankets are used to prevent/counter hypothermia. A threefold action facilitates this: The airtight foil reduces convection Heat loss caused by evaporation of perspiration is reduced To a limited extent the reflective surface inhibits losses caused by thermal radiation. In a hot environment they can be used to provide shade or provide protection against radiated heat, but using them to wrap a person would be counterproductive, because body heat would get trapped by the airtight foil; this effect would exceed. Space blankets are used to reduce heat loss from a person's body, but as they are constructed of PET film, they can be used for other applications for which this material is useful, such as insulating containers—e.g. for DIY solar projects—and other applications. In addition to the space blanket, the United States military uses a similar blanket called the "casualty blanket", it uses a thermal reflective layer similar to the space blanket, backed by an olive drab colored reinforcing outer layer.
It provides greater durability and warmth than a basic space blanket at the cost of greater bulk and weight. It is used as a partial liner inside the layers of bivouac sacks in cold weather climates. Space blankets are used by the Taliban to hide their heat signature from NATO forces. Thin-film deposition Thermoregulation Emissivity Thermal insulation Radiant barrier Reflectivity R-value Survival bag
A trowel is a small hand tool used for digging, smoothing, or moving small amounts of viscous or particulate material. Common varieties include the masonry trowel, garden trowel, float trowel. A power trowel is a much larger gasoline or electrically powered walk-behind device with rotating paddles used to finish concrete floors. Numerous forms of trowel are used in masonry and drywall construction, as well as applying adhesives such as those used in tiling and laying synthetic flooring. Masonry trowels are traditionally made of forged carbon steel, but some newer versions are made of cast stainless steel, which has longer wear and is rust-free; these include: Bricklayer's trowel has an elongated triangular-shaped flat metal blade, used by masons for leveling and shaping cement and mortar. Pointing trowel, a scaled-down version of a bricklayer's trowel, for small jobs and repair work. Tuck pointing trowel is long and thin, designed for packing mortar between bricks. Float trowel or finishing trowel is rectangular, used to smooth, level, or texture the top layer of hardening concrete.
A flooring trowel has one pointed end, made to fit corners. A grout float is used for working grout into gaps in floor and wall tile. Gauging trowel has a rounded tip, used to mix measured proportions of the different ingredients for quick set plaster. Pool trowel is a flat-bladed tool with rounded ends used to apply coatings to concrete on swimming pool decks. Margin trowel is a small rectangular bladed tool used to move and smooth small amounts of masonry or adhesive material. Notched trowel is a rectangular shaped tool with spaced notches along one or more sides used to apply adhesive when adhering tile, or laying synthetic floor surfaces. Other forms of trowel include: Garden trowel, a tool with a pointed, scoop-shaped metal blade and wooden, metal, or plastic handle, it is used for breaking up earth, digging small holes for planting and weeding, mixing in fertilizer or other additives, transferring plants to pots. Cathole trowel is used for burying personal waste in the backcountry, they are made of lighter weight materials than gardening trowels to make them easier to carry.
They may have features such as ruled sides to measure for proper cathole depth or jagged edges for cutting through roots or frozen soil. Some cathole trowels are designed to fold-up or collapse into a smaller size for easier storage. Others allow for items such as toilet paper to be stored inside the handle. In archaeology brick or pointing trowels are used to scratch the strata in an excavation and allow the colours of the soil to be clear, so that the different strata can be identified and excavated. In the United States, there are several preferred brands of pointing trowels, including the Marshalltown trowel. Taping knife, a drywall tool with a wide blade for spreading joint compound Putty knife, a smaller and variously shaped tool used in a variety of applications Palette knife, a smaller but shaped tool used in oil painting