Armillary sphere
In 1734 Pierre Vinon, instrument-maker and scientist, come to St. Petersburg together with Joseph-Nicolas De l'Isle, one of the first Russian academicians. Pierre Vinon had constructed the first armillary sphere in Russia. The device in these photos is direct descendant of the Pierre Vinon sphere. It is the latest one among its analogues.
The armillary sphere (in Latin - consisting of circles) is an astronomical device main function of which is visualization of our ideas on the world structure. In particular it can work as sundial. Besides, as a symbol of knowledge, armillary sphere has long been used as an indispensable attribute of portrait of a man of science, political figure and even a monarch.
If you buy a sundial as a gift, do not forget, please, to order an anniversary line. At the appointed day the shade on a sundial face will move along a specially calculated line. It may be a birthday, wedding day, or any other day you like.
According to acenturies-old tradition a motto or a dedication is advisable on a sundial face. You may choose a motto from the list or suggest your own one. Mottoes and anniversary lines etched on sundials in stock are free.
The duration of solar day is changeable within a year. Thus the difference between clock and sundial indications may be as high as 15 min depending on the season. You may easy convert solar time into mean time and vice versa using the equation of time table or graph. Usually I make it of brass, copper or stone.
