Censer

A censer, incense burner, perfume burner or pastille burner is a vessel made for burning incense or perfume in some solid form. They vary greatly in size, form, and material of construction, and have been in use since ancient times throughout the world. They may consist of simple earthenware bowls or fire pots to intricately carved silver or gold vessels, small table top objects a few centimetres tall to as many as several metres high. Many designs use openwork to allow a flow of air. In many cultures, burning incense has spiritual and religious connotations, and this influences the design and decoration of the censer.
Often, especially in Western contexts, the term "censer" is used for pieces made for religious use, especially those on chains that are swung through the air to spread the incense smoke widely, while the term "perfume burner" is used for objects made for secular use. The original meaning of pastille was a small compressed mixture of aromatic plant material and charcoal that was lit to release the odour, and pastille-burners were designed for this, for use in the home. Pastilles were made at home until their heyday in the early 19th century, and the burners are often made in ceramic.
Some types could also be used as pomanders, where the perfume diffuses slowly by evaporation rather than burning.

Use

For direct-burning incense, pieces of the incense are burned by placing them directly on top of a heat source or on a hot metal plate in a censer or thurible.
Indirect-burning incense, also called "non-combustible incense", is a combination of aromatic ingredients that are not prepared in any particular way or encouraged into any particular form, leaving it mostly unsuitable for direct combustion. The use of this class of incense requires a separate heat source since it does not generally kindle a fire capable of burning itself and may not ignite at all under normal conditions. This incense can vary in the duration of its burning with the texture of the material. Finer ingredients tend to burn more rapidly, while coarsely ground or whole chunks may be consumed very gradually as they have less total surface area. The heat is traditionally provided by charcoal or glowing embers.
For home use of granulated incense, small, concave charcoal briquettes are sold. One lights the corner of the briquette on fire, then places it in the censer and extinguishes the flame. After the glowing sparks traverse the entire briquette, it is ready to have incense placed on it.
For direct-burning incense, the tip or end of the incense is ignited with a flame or other heat source until the incense begins to turn into ash at the burning end. Flames on the incense are then fanned or blown out, with the incense continuing to burn without a flame on its own.
Censers made for stick incense are also available; these are simply a long, thin plate of wood, metal, or ceramic, bent up and perforated at one end to hold the incense. They serve to catch the ash of the burning incense stick.
In Taoist and Buddhist temples, the inner spaces are scented with thick coiled incense, which are either hung from the ceiling or on special stands. Worshipers at the temples light and burn sticks of incense. Individual sticks of incense are then vertically placed into individual censers.

Chinese use

The earliest vessels identified as censers date to the mid-fifth to late fourth centuries BCE during the Warring States period. The modern Chinese term for "censer," xianglu, is a compound of xiang and lu. Another common term is xunlu. Early Chinese censer designs, often crafted as a round, single-footed stemmed basin, are believed to have derived from earlier ritual bronzes, such as the dou 豆 sacrificial chalice.
Among the most celebrated early incense burner designs is the hill censer, a form that became popular during the reign of Emperor Wu of Han. Some scholars believe hill censers depict a sacred mountain, such as Mount Kunlun or Mount Penglai. These elaborate vessels were designed with apertures that made rising incense smoke appear like clouds or mist swirling around a mountain peak. The Han dynasty scholar Liu Xiang composed an inscription describing a hill censer:

I value this perfect utensil, lofty and steep as a mountain! Its top is like Hua Shan in yet its foot is a bronze plate. It contains rare perfumes, red flames and green smoke; densely ornamented are its sides, and its summit joins azure heaven. A myriad animals are depicted on it. Ah, from it sides I can see ever further than Li Lou .

Another popular design was the small "scenting globe", a device similar to a pomander, but used for burning incense. The famed inventor and craftsmen, Ding Huan, is believed to have made these with gimbal supports so the censer could easily be used to fumigate or scent garments. This is described by Edward H. Schafer:

"Censing baskets" were globes of hollow metal, pierced with intricate floral or animal designs; within the globe, an iron cup, suspended on gimbals, contained the burning incense. They were used to perfume garments and bedclothes, and even to kill insects.

Other Chinese censers are shaped like birds or animals, sometimes designed so that the incense smoke would issue from the mouth. During the medieval period when censers were more commonly used in Buddhist and Daoist rituals, hand-held censers fashioned with long handles were developed.
Archeologists have excavated several censers from Han era tombs that contained aromatics or ashen remains. Some of these aromatic plants have been identified as maoxiang, gaoliangjiang, xinyi, and gaoben. Scholars speculate burning these grasses "may have facilitated communication with spirits" during funeral ceremonies.
According to the Sinologist and historian Joseph Needham, some early Daoists adapted censers for the religious and spiritual use of cannabis. The Daoist encyclopedia Wushang Biyao, recorded adding cannabis into ritual censers. The Shangqing School of Daoism provides a good example. The Shangqing scriptures were written by Yang Xi during alleged visitations by Daoist "immortals", and Needham believed Yang was "aided almost certainly by cannabis". Tao Hongjing, who edited the official Shangqing canon, also compiled the Mingyi bielu. It noted that mabo, "are very little used in medicine, but the magician-technicians say that if one consumes them with ginseng it will give one preternatural knowledge of events in the future." Needham concluded,

Thus all in all there is much reason for thinking that the ancient Taoists experimented systematically with hallucinogenic smokes, using techniques which arose directly out of liturgical observance. … At all events the incense-burner remained the centre of changes and transformations associated with worship, sacrifice, ascending perfume of sweet savour, fire, combustion, disintegration, transformation, vision, communication with spiritual beings, and assurances of immortality. Wai tan and nei tan met around the incense-burner. Might one not indeed think of it as their point of origin?

These Waidan and neidan are the primary divisions of Chinese alchemy.
During the T’ang period, incense was used by upper-class people for personal hygiene, romantic rendezvous, and deodorizing the interior of edifices. These included places of worship, dwellings, and work-spaces. Dating back to the seventh century AD, the kuanhuo ceremony took place, where people would cleanse their homes with incense. However, in some parts of East Asia, incense burners were used as a way to tell time.
In the Far East, incense was used as a way to tell time because it was a simple mechanism and generally not a fire hazard. Time increments were marked off on each incense stick to show how much time had passed, then placed in a ritual tripod vessel known as a ting. During imperial coronations, incense sticks would be used to tell how long the ceremony was. Other variations of incense is the spiral incense coil. The spiral incense coil was used to measure time for longer durations. One spiral equated to one night. This type of incense was mainly used by the five ‘night watches’ of the community. The length of their shifts and breaks were determined by the time increments marked off on the spirals.
Tiangong censers are used for religious reasons in China.

Middle East

Incense burners were used in both religious and secular contexts, but were more widely utilized in palaces and houses. The earliest known examples of dish-shaped incense burners with zoomorphic designs were excavated in Ghanza, while the earliest examples of zoomorphic incense burners are from 11th-century Tajikistan. It is most likely that this practice was inspired by Hellenistic style incense burners as well as the frankincense trade present in the Arabian peninsula since the 8th century BCE.
A wide variety of designs were used at different times and in different areas. Pottery and stone incense burners were the most common while those made of metals were reserved for the wealthy. Artisans created these incense burners with moulds or the lost-wax method. Openwork zoomorphic incense burners with lynx or lion designs were popular in the Islamic world; bronze or brass examples are found from the 11th century until the Mongol conquests of the 13th century. These were especially popular during the Seljuq period. The extensive use of the lynx's form for incense burners was due to their popularity as a hunting animal and as a pet in Muslim courts. The complexity of the piece would also make it fit into a palatial setting. This style of incense burners could measure about 22 cm; others like an example in the Metropolitan Museum of Art in New York measures 85 cm. The surface of the object would be decorated with bands of Arabic calligraphy which would imitate a tiraz. This bands of text could include the name of the artist and the patron as well as prayers and good wishes for the owner. To insert coals and incense the head would be removed; the openwork geometric design would then allow the scented smoke to escape. Depending on the size, the incense burner could be either carried on a tray or carried by using the tail as a handle.
In mosques, incense burners do not have a liturgical use or a specific design denoted for religious context. However, they are still an important part of rituals and weddings. Other religious groups in Middle East such as the Copts and Syriacs do have ceremonial uses for incense burners.