Historically about the plumbers by Wikipedia
Quick look in to the history of the plumbers, thanks to Wikipedia:
The word "plumber" dates from the Roman Empire. The Latin for lead is plumbum. Roman roofs used lead in conduits and drain pipes and some were also covered with lead, lead was also used for piping and for making baths. In medieval times anyone who worked with lead was referred to as a plumber as can be seen from an extract of workmen fixing a roof in Westminster Palace and were referred to as plumbers "To Gilbert de Westminster, plumber, working about the roof of the pantry of the little hall, covering it with lead, and about various defects in the roof of the little hall". Thus a person with expertise in working with lead was first known as a Plumbarius which was later shortened to plumber.
How to check the status of hydraulics?
Any equipment or installation is exposed to some specific defects that occur during its use. Many of them can be easily repaired, but some require our specialized knowledge and skills. To avoid such problems, which can be particularly troublesome when it comes to plumbing, it is appropriate to deal with installations. To this end, regular checks and inspections, so that potential failures are detected before they even occur. Such inspections simply call the appropriate service to on-site check everything thoroughly. All it will take a little time, and with such a service gain confidence that will not meet us serious problem.
Worth to know
A plumber's snake is a slender, flexible auger used to dislodge clogs in plumbing. The plumber's snake is often reserved for difficult clogs that cannot be loosened with a plunger. It is also sometimes called a toilet jack or electric eel.
Plumber's snakes have a coiled (helix-shaped) metal wire with a broader gap between the coils at the terminal end. The operator turns a crank to rotate the helix as it moves through the pipe.
If the clog is caused by a dense, but shreddable obstacle, such as tree roots or glass wool, the auger might break it up enough to enable flow. A small, lightweight obstruction might be snagged or corkscrewed by the auger, enabling the operator to pull it away. As the auger rotates, it also flails against the interior walls of the pipe, scraping off minerals and oil.