or Hevelke, (John), an eminent astronomer, was born at Dantzig in 1611. He studied in Germany, England, and France, and everywhere obtained the esteem of the learned. He was the first that discovered a kind of libration in the moon, and made several important observations on the other planets. He also discovered several fixed stars, which he named the firmament of Sobiejski, in honour of John III. king of Poland. His wife was also well skilled in astronomy, and made a part of the observations published by her husband. In 1673 he published a description of the instruments with which he made his observations, under the title of Machinae Caelstis: and in 1679 he published the second part of this work; but in September the same year, while he was at a seat in the country, he had the misfortune to have his house at Dantzig burnt down. By this calamity he is said to have sustained a loss of several thousand pounds; having not only his observatory and all his valuable instruments and apparatus destroyed, but also a great number of copies of his Machinae Caelstis; which accident has made this second part very scarce, and consequently very dear. In the year 1690 were published Firmamentum Sobiejcianum, and Prodromus afronoricum & novae tabulae solaris, una cum catalogo fixarum, in which he lays down the necessary preliminaries for taking an exact catalogue of the stars. But both these works are posthumous; for Hevelius died in 1687, on his birthday, aged 76. He was a man greatly esteemed by his countrymen, not only on account of his great reputation and skill in astronomy, but as a very excellent and worthy magistrate. He was made a burgomaster of Dantzig; which office he is said to have executed with the utmost integrity and applause. He was also very highly esteemed by foreigners; and not only by those skilled in astronomy and the sciences, but by foreign princes and potentates: as appears abundantly from a collection of their letters which were printed at Dantzig in the year 1683.