Miniature -poon computer, abacus H93 - pendant A miniature mechanical tide computer - a reproduction of a device from 1570. built by Humphrey Cole, the original is kept in the British Museum in London. Wed 50mm, depth. 6mm, weight 60gr. Made of zamak and brass, varnished using the technique from several hundred years ago. Abacus, a device that allows you to predict the time of the appearance of sea tides. The instrument consists of a fixed dial marked with degrees from 0 to 360, an hour scale and a wind rose. There are 2 movable discs mounted on it. One - specifying the lunar month with a scale of 1-30 and the other with the pointer showing the shape of the moon, which changes as the pointer moves. The device takes into account the direction of the wind, the number of days since the new moon, the current age of the moon, which allows you to predict sea tides. On the other side of the device there is a beautiful wind rose. A great gift for a sailor, fisherman, astronomer or enthusiast of technical monuments. User manual in English, French, Italian and Spanish. A product of the Spanish company Hemisferium. The set includes an attractive decorative box with an insert on which the device rests.