The tip of the marker where ink comes out from is usually made of cloth. This allows the ink to go through easily. A lot of ink can come out from it at one time.
Anchor
Anchors are used to stop boats from moving. Today, anchors are usually made of metal, and they are made to catch the ocean floor (the seabed).
There are two main types of anchors: temporary and permanent. A permanent anchor is called a "mooring block" and is not easily moved. A temporary anchor can be moved and is carried on the boat. When people talk about anchors, they are usually thinking about temporary anchors.
An anchor works by either weight (mass) or shape. Shape is more important to temporary anchors, and design is very important. Anchors must resist wind and tide, and also the up-and-down movement of waves.
The oldest anchors were just rocks, and many rock anchors have been found from a long time ago. Many modern moorings still use a large rock as the mooring block.
A simple anchor which uses two arms made of wood, and a rock weight, is an anchor which is still used today. The wood arms are sharp to enter the seabed, and the weight will hold normal movement.
The English language uses several special words to describe parts of anchors. This is because England has a rich marine and naval history, and so the language gives a large number of words to boat and ship terminology.
A modern temporary anchor usually has a middle bar called the "shank", attached to a flat surface (traditionally called "fluke") which holds the seabed. The place where the shank meets the fluke is called the "crown", and the shank is usually fitted with a ring or shackle to attach it to the "rode" (cable, chain, or rope joining the anchor to the boat). Some old anchors have attached to the shank a "stock", which is a bar that places the anchor in a certain way when it falls on the seabed. Old anchors are often named "stocked" or "stockless" anchors depending on whether they have this, or not.
There are many designs.
Over the last 20 years, many new anchor designs have appeared. These anchors are usually designed for small vessels, and are usually not for large ships. See modern designs.
The Fisherman has a traditional design that has not changed much over time. It is less useful than a good modern design, and its holding power for its weight is among the worst of all anchor types.
The most common type of fluke anchors is the "Danforth". The Danforth style uses a stock at the crown (see above), to which two large flat flukes are attached. The stock can rotate, so the flukes can move toward the bottom. It can hold very well but has difficulty "setting" (entering the seabed) on its own. It is efficient for its weight.
Fluke anchors have difficulty penetrating kelp and weed seabeds, as well as very hard sand or clay seabeds. Once set, the anchor can come free and fail to "reset" on its own.
A traditional design, the grapnel style is simple to design and build. It is a simple hook that is good for rock or reefs. It is useless for most other seabeds.
The original "CQR" was invented in 1933 in the United Kingdom. Many copies of it now exist. Plows used to be popular with sailors and private boaters. They are good but not excellent in most seabeds. Another more recent design is the "Delta" which is better.
Plows use a special weight in the tip of the fluke (the "toe") for them to work properly. This makes them heavy.
The genuine CQR and Delta brands are now owned by Lewmar.
The genuine Bruce was invented in the 1970s and to try to solve some problems of the plow. Many copies are now made. This type of anchor is now called a "claw-type". Claw anchors can set quickly in some seabeds, but do not hold well for their weight, and can let go very suddenly.
Bruce Anchor Group no longer make the genuine Bruce. Most copies are lower quality than the genuine Bruce.
Modern anchors are designed to be better than the plow and claw types. Many are new, still under patent and owned by commercial companies or tied to certain brands.
Many modern designs are better than the older types. This chart shows tests done by West Marine (an American marine shop) in 2006 . The anchors were tested on three different sandy seabeds, at three different "scopes" (pull angles).
Six of the seven best anchors on this chart are "modern", but several modern anchors did very badly. This shows that 'newer' is not always better.
Permanent anchors are used when a floating thing must be kept in place for a long time. They are used to anchor Lightships, navigation buoys, and moorings. The anchor must hold in all weather, even the worst storm.
A deadweight anchors is a heavy weight. It can be used when the bottom is too hard for other types of anchors. It can be made of a large rock or a concrete block.
Mushroom and pyramid anchors are good where the seabed is soft. This type of anchor needs time to dig into the seabed. It can be smaller and lighter than a deadweight anchor. The mushroom anchor is shaped like a mushroom, and the pyramid anchor is shaped like a pyramid with the apex pointing down.
The sand screw must be screwed into the seabed before it is used. It can be very light.
Light pollution
Light pollution is a type of pollution. It is defined as “any adverse (or bad) effect as a result of man-made lights.” Usually, this means too much light. Several species, including plants and humans, are badly affected by light pollution. Most people have never heard of light pollution, and those who have usually don’t care, or do anything about it. Light pollution costs Americans billions of dollars every year.
There are five kinds of light pollution:
Sky glow usually has more of an effect on the environment than light trespass and glare, but all of them are a major problem to people today.
Sky glow is the kind of light pollution that prevents people from seeing stars and other deep-space objects. This causes birds to not be able to migrate to the right place because they can not follow the moon and stars. Sky glow also prevents astronomers from seeing dim objects.
Light trespass is when light being used by a person goes into the property of another. Although light trespass is not an environmental issue, it is still light pollution.
The third kind of light pollution, glare, has different kinds. The first, disability glare, is the loss of visibility because of too many lights. Discomfort glare is when the lights cause pain.
Light pollution stops migrating birds from having any way of seeing the moon and stars that they need to use to navigate the direction of their migration, therefore not being able to migrate to the correct place. Also, sea turtles do not come to shore and nest as often, because they are afraid of the lights. It also affects animals eyes as a flash of camera weakens the eyesight of animals.
Glare causes sleep problems in humans. For example, too much light in an apartment shining in from a nearby billboard will disturb their sleep. Science, too, is being affected by light pollution. Astronomers have no way of observing or making discoveries with too much light to block the night sky.
Light pollution also causes headaches when light directly falls into our eyes and affects the sensory nerves.
There are now several groups that are trying to prevent light pollution. Light pollution first made news in 1964, when an observatory was specially placed just to avoid light pollution. However, it wasn’t brought to the attention of most people until June 6, 2002, when the Czech Republic passed the world’s first light pollution law. Since then, light pollution is slowly being recognized by the general public as a major problem.
Also government should pay attention for advertisements, which produce the greatest amount of light.
You can lower the amount of light pollution by having lights off when they are not needed. You can also shield yourself from this pollution by putting curtains on a window facing the street or any other disturbing light source.