Hemisferium Universal de Rojas astrolabe (25041)

This instrument is a reproduction of the universal astrolabe designed by Juan de Rojas y Sarmiento, a Spanish astronomer and mathematician, in the 16th century. In 1550, Rojas introduced the orthogonal projection to Europe, which was successfully applied in this universal astrolabe. Unlike earlier models, this design offered the advantage of being usable at any latitude, making it a versatile and groundbreaking tool for its time.

Function:
An astrolabe is an ancient astronomical device used to solve problems related to time and the positions of celestial bodies. It represents the sky at a specific location and time by projecting it onto the face of the instrument. By adjusting its moving parts to a particular date and time, users can access detailed information about visible and invisible celestial phenomena. Common uses include determining the time of day or night, calculating sunrise or sunset times, and identifying star positions. While not primarily a navigation tool, it differs from the mariner's astrolabe widely used during the Renaissance.

History:
The astrolabe's origins date back over 2000 years. The principles of stereographic projection were understood as early as 150 BC, and accurate instruments were made by 400 AD. The astrolabe reached its peak development in the Islamic world around 800 AD and was introduced to Europe via Islamic Spain (al-Andalus) in the early 12th century. It remained the most popular astronomical instrument until around 1650 when more precise tools replaced it.

Accuracy:
This reproduction features an updated sky map for the 21st century and is fully functional. Its accuracy is rated as excellent for Northern latitudes and moderate for Southern latitudes. The instrument combines historical significance with meticulous craftsmanship and comes with a wooden base and an instruction manual available in English, French, Spanish, and Italian.

Specifications:

• General Dimensions:

  • Colour: Gold/Brown

  • Height: 250 mm

  • Width: 200 mm

  • Length: 250 mm

  • Weight: 1620 grams

• Material: Metal