Big brass astrolabe Rojas H34 - reproduction, diam. 20cm. A legendary medieval computer, a precise navigation device and an astronomical instrument. Universal astrolabe for the northern hemisphere built on the basis of the model of the Spanish mathematician Juan de Rojas - model from 1550. Sky map modernized. The device can be used for actual measurements. Renaissance style. Max height 24.5cm, width 20cm, depth 0.7cm. The device is fully functional. It was handcrafted in the same way as the astrolabes several hundred years ago. An astrolabe is an astronomical computer that determines time from the position of the sun and stars. Thanks to it, it was possible to find out what time it is centuries ago. This trivial question was once, in the pre-smartphone era, a great challenge. Thanks to it, it was possible to determine the time of phenomena such as sunrises and sunsets, it made it possible to determine the position of stars and directions. It was used to create many advanced calculations. There were about 400 of them. The astrolabe was also a popular navigation device. The astrolabe recreates a 3D sky map on a flat surface. Its story began over 2,000 years ago. Over the centuries, knowledge was developed and increasingly complex devices were built. Much of this is due to Arab scholars. Sources say that thanks to this device, for example, a very detailed map of Baghdad was created in the Middle Ages. It is thanks to them that in the 12th century the astrolabe came to Europe. It was the most common astronomical instrument until around 1650, then it was replaced by more precise instruments. Our astrolabe is distinguished by attention to detail, high historical value and elegant workmanship. It is delivered complete with a wooden pedestal. At this link, a video describing the operation of the astrolabe: https://www.ted.com/talks/tom_wujec_demos_the_13th_century_astrolabe?language=pl