Worth to know
A drain cleaner is a chemical-based consumer product that unblocks sewer pipes or helps to prevent the occurrence of clogged drains. The term may also refer to the individual who uses performs the activity with chemical drain cleaners or devices known as plumber's snake. Drain cleaners can be classified in two categories: chemical, or device.
If a single sink, toilet, or tub or shower drain is clogged the first choice is normally a drain cleaner that can remove soft obstructions such as hair and grease clogs that can accumulate close to interior drain openings. Chemical drain cleaners, plungers, handheld drain augers, air burst drain cleaners, and home remedy drain cleaners are intended for this purpose.
If more than one plumbing fixture is clogged the first choice is normally a drain cleaner that can remove soft or hard obstructions along the entire length of the drain, from the drain opening through the main sewer drain to the lateral piping outside the building. Electric drain cleaners and sewer jetters are intended for this purpose.
Each type of drain cleaner has advantages, disadvantages, and safety considerations as described below.
Central heating - history
The ancient Greeks originally developed central heating. The Temple of Ephesus was heated by Flues planted in the ground and circulating the heat which was generated by fire. Some buildings in the Roman Empire used central heating systems, conducting air heated by furnaces through empty spaces under the floors and out of pipes in the walls?a system known as a hypocaust.23
The Roman hypocaust continued to be used on a smaller scale during late Antiquity and by the Umayyad caliphate, while later Muslim builders employed a simpler system of underfloor pipes.4
After the collapse of the Roman Empire, overwhelmingly across Europe, heating reverted to more primitive fireplaces for almost a thousand years.
In the early medieval Alpine upland, a simpler central heating system where heat travelled through underfloor channels from the furnace room replaced the Roman hypocaust at some places. In Reichenau Abbey a network of interconnected underfloor channels heated the 300 m? large assembly room of the monks during the winter months. The degree of efficiency of the system has been calculated at 90%.5
In the 13th century, the Cistercian monks revived central heating in Christian Europe using river diversions combined with indoor wood-fired furnaces. The well-preserved Royal Monastery of Our Lady of the Wheel (founded 1202) on the Ebro River in the Aragon region of Spain provides an excellent example of such an application.
Documented early plumbing systems for bathing go back as far as around 3300 BC with the discovery of copper water pipes beneath a palace in the Indus Valley Civilization of ancient India; see sanitation of the Indus Valley Civilization. Evidence of the earliest surviving personal sized bath tub was found on the Isle of Crete where a 1.5-metre (5 ft) long pedestal tub was found built from hardened pottery.
The clawfoot tub, which reached the apex of its popularity in the late 19th century; had its origins in the mid 18th century, where the ball and claw design originated in Holland, possibly artistically inspired by the Chinese motif of a dragon holding a precious stone. The design spread to England where it found much popularity among the aristocracy, just as bathing was becoming increasingly fashionable. Early bathtubs in England tended to be made of cast iron, or even tin and copper with a face of paint applied that tended to peel with time.1
The Scottish-born inventor David Buick invented a process for bonding porcelain enamel to cast iron in the 1880s while working for the Alexander Manufacturing Company in Detroit. The company, as well as others including Kohler Company and J. L. Mott Iron Works, began successfully marketing porcelain enameled cast-iron bathtubs, a process that remains broadly the same to this day. Far from the ornate feet and luxury most associated with clawfoot tubs, an early Kohler example was advertised as a "horse trough/hog scalder, when furnished with four legs will serve as a bathtub." The item's use as hog scalder was considered a more important marketing point than its ability to function as a bathtub.1
In the latter half of the 20th century, the once popular clawfoot tub morphed into a built-in tub with a small apron front. This enclosed style afforded easier maintenance and, with the emergence of colored sanitary ware, more design options for the homeowner. The Crane Company introduced colored bathroom fixtures to the US market in 1928,citation needed and slowly this influx of design options and easier cleaning and care led to the near demise of clawfoot-style tubs.