GUG 



GUG 



dication of the anger of Heaven, and a 

 just punishment inflicted upon him for his 

 impiety. He was the author of several 

 treatises in natural philosophy, the prin- 

 cipal of which is entitled " Experimenta 

 Magdeburgica," 1672, folio, and contains 

 his experiments on a vacuum. 



GUETTARDA, in botany, a genus of 

 the Monoecia Heptandria class and order. 

 Natural order of Tricoccx. Rubiaceae, 

 Jussieu. Essential character: calyx cylin- 

 dric ; corolla six or seven cleft, funnel- 

 shaped ; pistil one ; drupe dry. There 

 are four species, natives of the East and 

 West Indies. 



GUGLIELMINI (DOMINIC), an eminent 

 Italian mathematician and civil engineer, 

 was descended from an honourable fami- 

 ly, and born at Bologna in the year 1655. 

 His favourite studies were the mathema- 

 tics and medicine, in the former of which 

 he had for tutor the celebrated M. Germ. 

 Montanari ; and in the latter, the illus- 

 trious Malpighi. He entered into the 

 dispute between M. Montanari and M. 

 Carina, concerning the extraordinary 

 luminous meteor which was observed in 

 most parts of Italy in 1676, and support- 

 ed the opinions of his master. In the 

 year 1678 he was admitted to the de- 

 gree of doctor of medicine by the uni- 

 versity of Bologna. Upon the appear- 

 ance of the remarkable comet in the 

 years 1680 and 1681, he published a 

 treatise " De Cometarum Natura et Or- 

 tec," &c. 1681, in which he proposed 

 a new system on the subject, which he 

 thought would serve to explain all the 

 phenomena of those heavenly bodies; 

 but it did not meet with the approba- 

 tion of the scientific world. His next 

 astronomical treatise, containing remarks 

 on the solar eclipse which took place on 

 the 12th of July, 1684, and which he 

 published in Latin, at Bologna, in the 

 same year, reflected greater credit on his 

 knowledge and accuracy of observation. 

 Soon afterwards the Senate of Bologna 

 appointed him principal professor of 

 mathematics in the university of that 

 city, and in the year 1686, created him 

 intendant-general of the rivers of the 

 Uolognese. The office last mentioned 

 engaged him to pay more particular at- 

 tention to the study of hydrostatics and 

 hydraulics; in consequence of which, in 

 the year 1690, he published the first 

 part, and in the following year the se- 

 cond part, of an excellent hydrostatical 

 treatise, ent itled " Aquarum Fluentium 

 Mensura, Novo Methodolnquisita." Some 

 of his observations in this work were at- 



tacked by M. Papin, who also entered 

 into a contest with the author on the 

 subject of Syphons. Their difference iu 

 opinion gave rise to two letters by Gugli- 

 elmini, which were printed under the ti- 

 tle of " Epistolx Dux Hydrostatics." He 

 was engaged in settling the differences 

 which arose between the cities of Bo- 

 logna and Ferrara, respecting the man- 

 agement of the embankments and sluices 

 in their contiguous districts ; and receiv- 

 ed as a reward of his services, from his 

 native city, the appointment to a new 

 office in the university, which was that 

 of professor of hydrometry. In the year 

 1695 he assisted M. Cassini in repairing 

 the famous meridian line, which he had 

 constructed forty years before in the 

 church of St. Petronius, at Bologna ; on 

 which occasion our author published a 

 memoir, descriptive of the method pur- 

 sued in laying it down, and establishing 

 its claims to correctness and accuracy. 

 In the year 1697 he published his grand 

 physico-mathematical treatise on the na- 

 ture of rivers, entitled " Delia Natura 

 de Fiumi," which raised his reputation 

 to the highest pitch, for correct scienti- 

 fic knowledge, ingenuity, and judgment 

 in hydraulics. Montucla commends it in 

 warm terms, and says that it ought to be 

 carefully studied by every person who 

 would wish to become thoroughly master 

 of this branch of science. The reputation 

 which Guglielmini acquired by this per- 

 formance occasioned his being employed 

 by the Dukes of Mantua, of Parma, and 

 Modena, the Grand Duke of Tuscany, 

 Pope Clement XL the Republics of Ve- 

 nice and Lucca, &c. in the invention and 

 construction of the necessary hydraulic 

 works in their respective territories. In 

 the year 1698 he was induced, by the 

 Republic of Venice, to accept of the ma- 

 thematical chair in the university of Pa- 

 dua ; but the senate of Bologna decreed 

 that he should still retain, notwithstanding 

 his new employment, the title of profes- 

 sor in their university, and the emolu- 

 ments annexed to it. In the year 1702, 

 he exchanged his mathematical chair at 

 Padua for the more lucrative one of me- 

 dicine ; after which he published diffe- 

 rent treatises on medical and chemical 

 subjects, &c. He died at Padua in 1710, 

 in the fifty-fifth year of his age. He 

 had been admitted a member of the 

 Academy of Sciences at Paris in the year 

 1696, and was also associate or corres- 

 ponding member of the Academiesof Ber- 

 lin and Vienna, and of the Royal Society 

 at London. The best edition of his trea- 



