The tellurium is a mechanical representation of the Earth-Moon-Sun system that reproduces the relative movement of the three bodies. This model allows us to visualize the causes of night and day, the seasons, solar and lunar eclipses and the phases of the Moon, according to the relative position of the Earth respect to its satellite and the Sun.

Hand-made piece Materials: brass, copper and beech wood. Dimensions: h=25 cm. Design: Marc Boada.

"A plumb line in rest indicates, by the direction of the thread, the direction of gravity in the place in which it stands. In two distinct places many kilometers apart the same fact can be observed: that the vertical line is perpendicular to the surface of still water. As the Earth is noticeably spherical, it may be concluded that the vertical lines or directions of gravity always go directly towards the center of the Earth." (GarcÕa Francos, Planet Earth, 1923).

Although the definition is correct, it should not be forgotten that the Earth rotates and that the plumb will therefore always undergo a certain maximum deviation in the equator and minimum deviation at the poles.

Hand-made piece. Dimensions of the plump with base: Dimensions of the medium plump: 8 cm Dimensions of the small plump: 4,5 cm Dimensions of the sperical plum: 5,5 cm Materials: Brass and old walnut wood. Design: Marc Boada

The anemoscope is an apparatus used to indicate the wind direction. The best-known nowadays are the light, white and red-striped woven sleeves that indicate wind direction on the freeways. The one before you is a faithful reproduction of the original, constructed at the beginning of the XVIII century. It is today in the Museum of Science and Technology in Florence.

Hand-made piece. Materials: Brass, copper and American walnut wood. Dimensions: h=41 cm. Scale: 1/2 Design: Anonymous.

Hygrometers are instruments for measuring atmospheric humidity. This instrument is a weighing scales that balances a hygroscopic substance like cotton in one of plates and a wax ball that does not absorb water in the other. It is used, as Leonardo da Vinci wrote, "to know the quality of air when it is going to rain" since, in these conditions, the cotton absorbs the humidity of the atmosphere, and the scales goes out of balance.

It is not known for sure if Leonardo made this instrument or if he simply designed it.

 

Hand-made piece. Materials: Wood of walnut, brass, bone, wax and cotton. Dimensions: h=3­m Design: Leonardo da Vinci

The principle of the Saussure's hygrometer consists in a hair without grease fixed to the frame at the top and to a weight at the bottom. The weight is connected by amplifying handles to a transmission system that finishes in a signaler that, moving on a scale, indicates the relative humidity.

When the air is dry, the cells of the hair are together one with another; but when the air is humid the spaces between the cells absorb water vapor and the hair increases in its thickness and length. This extension is the one that is used to measure the humidity.

 

 

Hand-made piece. Materials: wood, brass, ivory, horse hair. Dimensions: h=38,5cm Design: Horace-Bœnœdict de Saussure, 1775.

Watch described in a treaty on sundials written by Al-Raqqam in the 14th century. It does not exist more reference that its literary description.

It consists of a sheet of brass engraved with a gnomonic outline, suspended of three threads to prevent every reasoning and provided in its interior with a magnetic mineral one capable of orientating the set as if about a compass people were.

Piece prepared by hand. Materials: bronze, magnetite, wood thread. Dimensions: h= Design:

A fractal is a mathematical object of great complexity defined by simple algorithms. The fractals were studied in a long way by Benoît B. Mandelbrot (Poland, 1924) in the attempt to describe objects of the nature whose fractional dimensions had been considered curiosities in the mathematics. In fact, the fractal term is an adaptation of the fractional term. If a line has a dimension, a plan has two and a volume has three, in the fractals dimensions that can be written in the form of fraction appear (p.e. 7/4, which would correspond to a body that is between a line and a plan).

The techniques of fractales have been used in the compression of images, like this as in metereology, geography and other scientific disciplines.

The process for its creation is that we place an impurity of 0,3 mm of thickness in the center of a plaque and afterwards a quantity dosed of glue and afterwards the other plaque|plate. Pressure is applied during some seconds and it releases itself afterwards penetrating air.

Part prepared by hand. Materials: methacrylate, velvet, bronze and glue/tail. Dimensions: h= 18,5 cm Design: Marc Boada, 2005