What Is a Solarium?
A solarium may be a sundial. It may also be a terrace, a balcony or a room exposed to the rays of the sun, especially one used for the treatment of illness by sunbathing. A solarium (also sun-room, garden room) is a structure, either attached or integrated into a building such as a home, restaurant, or office, which allows enjoyment of the surrounding landscape while being sheltered from adverse weather.
Also known as a sun parlor, sun porch, patio room, Florida room, garden conservatory, or winter garden, such rooms are popular in the United States, Europe, Canada, Australia, and New Zealand. A portico is also sometimes called a porch. In Great Britain, with its long history of formal conservatories, small scale “sunrooms” are also sometimes known by that term. Sunrooms are used in passive solar building design as a technique for heating and lighting structures.
The fact that the sun’s rays may be beneficial to man was not scientifically proved until fairly recently. Vitamin D is now known to be activated by the ultra-violet rays in sunlight. Nevertheless, in the late 19th Century, it was observed that many people found “sunshine baths” of great help when recovering from an illness. Many hospitals and large private houses had solariums or sun rooms.
The rays of the sun not only induced a feeling of well-being, but helped to clear up some skin diseases and imparted a glowing color to the body. Before this time, a light, delicate complexion had been a mark of wealth, an indication that one had no need to toil in all weathers to earn a living.
A sundial tells the time by means of the shadow cast by the sun’s rays. The earliest known sundial still preserved is an Egyptian shadow clock dating from at least the 8th Century B.C. The Greeks and Romans constructed very complex sundials, and the Renaissance produced many beautiful designs.
The Solarium Augusti (also called Horologium Augusti) was an ancient Roman monument in the Campus Martius constructed during the reign of Augustus. It functioned as a giant solar marker, according to various interpretations serving either as a simple meridian line or as a sundial. It was erected by the emperor Augustus, with the 30-meter Egyptian red granite Obelisk of Montecitorio, which he had brought from Heliopolis in ancient Egypt.
The obelisk was employed as a gnomon that cast its shadow on a marble pavement inlaid with a gilded bronze network of lines, by which it was possible to read the time of day according to the season of the year. The solarium was dedicated to the Sun in 10 BCE, shortly after Julius Caesar’s calendar reform. It was the first solar dedication in Rome.
By the 19th Century, clocks and watches were so accurate that the sundial was used only as an ornament in gardens. But some especially designed for scientific purposes were made as late as the beginning of the 20th Century.