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.

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 19^th 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.

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 8^th Century B.C.

The Greeks and Romans constructed very complex sundials, and the Renaissance produced many beautiful designs. By the 19^th Century, clocks and watches were so accurate that the sundial was used only as an ornament in gardens. But some specially designed for scientific purposes were made as late as the beginning of the 20^th Century.