Birth date: 
Birth place: 
Date of death: 
Place of death: 
1 Oct 1671 
Cremona, Italy 
4 July 1742 
Pisa, Italy 
Guido Grandi was educated first at the Jesuit college in Cremona. He became a member of the Order of the Camaldolese in 1687. This Order, an offshoot of the Benedictine Order, was founded about 1012 at Camaldoli near Arezzo, Italy. The monastery and the hermitage formed one unit in this Order and Grandi studied at one of these units in Ferrara. Then, in 1693, he went to another monastery of the Camaldolese Order in Rome. The following year, Grandi became a teacher of philosophy and theology at the Camaldolese monastery in Florence. Up to this time he had shown little interest in mathematics but now his thoughts turned in that direction. However he continued to teach philosophy being appointed professor in Rome in 1700, then going to Pisa again as professor of philosophy. Grandi's first mathematical appointment came in 1707 when he became mathematician to the Grand Duke of Tuscany, Cosimo III de' Medici. In 1709 he visited England and clearly impressed the English scientists since he was elected a Fellow of the Royal Society . In 1714 Grandi was appointed Professor of Mathematics at the University of Pisa. Grandi was the author of a number of works on geometry in which he considered the analogies of the circle and equilateral hyperbola . He also considered curves of double curvature on the sphere and the quadrature of parts of a spherical surface. In 1701 Grandi discussed the conical loxodrome , the curve that cuts the generators of a cone of revolution in a constant angle. He studied the curve the Witch of Agnesi in 1703. In fact his work of 1703 is important in introducing Leibniz 's calculus into Italy. In 1728 Grandi published Flores geometrici a work in which he defines the clelie curve. He named the curve after Countess Clelia Borromeo and dedicated his book to her. If the longitude and colatitude of a point P on a sphere is denoted by and and if P moves so that = m , where m is a constant, then the locus of P is a clelie. Grandi also applied the term "clelies" to the curves determined by certain trigonometric equations involving the sine function a sin = b sin m a sin = a  b sin m
Grandi also worked on hydraulics and was involved with a number of projects such as ones to drain the Chiana Valley and the Pontine Marshes. He also published a number of works on mechanics and astronomy. His practical work on mechanics included experimenting with a steam engine.
Source:School of Mathematics and Statistics University of St Andrews, Scotland
