Sharp

(Abraham), in biography, an eminent mathematician, mechanist, and astronomer, was descended from an ancient family at Little Horton, near Bradford, in the west. riding of Yorkshire, where he was born abont the year 1651. At a proper age he was put apprentice to a merchant at Manchester; but his genius led him so strongly to the: study of mathematics, both theoretical and_ practical, that he scon became uneasy in that situation of life. By the mutual-consent, therefore, of his master and himself, though not altogether with that of his father, he quitted the busine of a merchant.. Upon this he removed to Liverpool, where he gave himself up wholly to the study of mathematics, astronomy, . and where for a subsistence he opened a school, and taught writing and accounts, . He bad not been long at Liverpool, when he accidentally fell in company with a merchant, or tradesman, visiting that town from ‘London, in whose house it seems the astronomer Fiamsteedthen lodged. With the view, therefore, of becoming acquainted with this eminent man, Mr. Sharp engaged himself with the merchant as a book-keeper. In consequence he soon contracted an intimate acquaintance and friendship with Mr, Fiamsteed, by whose interest and recommendation he obtained a more profitable employment in the duck-yard at Chas am: where he continued till his friend and patron, knowing his great merit in astronomy and mechanics, called him to his a istance in contriving, adapting, and fitting up the astronomical apparatus ‘in the royal observatory at Green wich, which had been lately built, namely, about the year 1670; Mr. Flamsteed being then thirty years of age, and Mr. Sharp twenty-five. In this situation he continued to a ist Mr. Flamsteed in making observations (with the mural arch, of 80 inches radius, and 140 degrees on the limb, contrived and graduated by Mr. Sharp) on the meridional zenith distances of the fixed stars, sun, moon, and planets, with the times of their transits over the meridian; also the diameters of the sun and moon, and their eclipses, with those of Jupiter’s satellites, the variation of the compa , . He a isted him also in making a catalogue of near 3000. fixed stars, as to their longitudes and magnitudes, their right ascensions and polar distances, with the variations of the same while they change their longitude by one degree. But from the fatigue of continually observing the stars at night, in a cold thin air, joined 40. a weakly constitution, he was reduced.toa bad state of health; for the recovery of which he desired leave to retire to his house at Horton; where, as soon as he found himself on the recovery, he began to fit up an observatory of his own; having first made an elegant and curious engine for turning all kinds of work tn wood or bra , with a maundril for turning irregular figures, as ovals, roses; wreathed pillars, . Beside these, he made himself most of the tools used by joiners, clockmakers, opticians, mathematical instrument-makers, . The limbs or arcs of his large equatorial in str ament, sextant, quadrant, . he graduated with the nicest accuracy, by diagonal divis tons into. degrees and _minutes. The telescopes he made use of were all of his own making, and the lenses ground, figured, and adjusted with his own hands. It was at this time that he a isted Mr. Flamsteed in calculating, most of the tables in the second volume of his Hist or i a Ceelestis, as ap- ears by their letters, to be seen in the hands of Mr. Sharp’s friends at Horton. Likewise the curious drawings of the charts of all the constellations visible in our hemisphere, with the still more excellent drawings of the planispheres both of the northern and southern constellations. And though these drawings of the constellations were sent to be engraved at Amsterdam by a masterly hand, yet the originals far exceeded the engravings in point of beauty and elegance: these were published by Mr, Flamsteed, and both copies may be seen at Horton. The mathematician meets with something extraordinary in Sharp’s elaborate treatise of Geometry Improved (in 4to, 1717, signed A.S. Philomath.), Ist, by a large and accurate table of segments of circles, its construction and various uses in the solution of several difficult problems, with compendious tables for finding a true proportional part; and their use in these or any other tables exemplified in making logarithms for their natural numbers, to 60 places of figures; there being a table of them for all primes to 1100, true to 61 figures. 2d, His concise treatise of Polyedra, or solid bodies of many bases, both the regular ones and others: to which are added twelve new ones, with various methods of forming them, and their exact dimensions in surds, or species, and in numbers: illustrated with a variety of copper-plates, neatly engraved by his own hands. Also the models of these polyedra he cut out in box wood with amazing neatne and accuracy. Indeed few or none of the mathematical instrument-makers could exceed him in exactly graduating or neatly engraving any mathematical or astronomical instrument, as may be seen in the equatorial] instrument above mentioned, or in his sextant, quadrants and dials of various sorts; also in a curious armillary sphere, which, beside the common _ properties, has moveable circles, ., for exhibiting and resolving all spherical triangles; also his double sector, with many other instruments, all contrived, graduated and finished, in a most elegant manner, by himself. In short, he po ¢ ed at once a remarkably clear head for contriving, and an extraordinary hand for executing any thing, not only in mechdnics, but likewisé inf drawing, writing, and making the most exact® and beautiful schemes or figures in all his cal« culations and geometrical constructions. The quadrature of the circle was undertaken’ by him for his own private amusement in the year 1699, deduced from two different series, by which the truth of it was proved to 72 places of figures; as may be seen in the intro= duction to Sherwin’s tables of logarithms; that is, if the diameter of a circle be 1, the circumference will be found equal to3° 141592653589 79323846264338327950288419716939937510 582097409044592307816405, . In the same” book of Sherwin’s may also be seen his ingenious improvements on the making of logarithms, and the constructing of the natural sines, tangents, and secants. He also calculated the natural and log a< rithmic sines, tangents, and secants, to every second in the first minute of the quadrant: the laborious investigation of which may probably _ be seen in the archives of the Royal Society,- as they were presented to Mr, Patrick Murdoch for that purpose; exhibiting his very neat and accurate manner of writing and arranging his figures, not to be equalled perhaps by the best _ penman now living. Mr. Sharp kept up a@ Correspondence by letters with most of the eminent mathematicians’ and astronomers of his time, as Mr. Flamsteed, Sir Isaac Newton, Dr. Halley, Dr. Wallis, — Mr. Hodgson, Mr. Sherwin, 8c. the answers: to which letters are all written upon the backs, or empty spaces, of the letters he received, in a short-hand of his own contrivance. From a great variety of letters (of which a large chest’ full remain with his friends) from these and’ many other celebrated mathematicians, it is evident that Mr. Sharp spared neither pains” nor time to promote real science. Indeed, being one of the most accurate and indefatigable computers that ever existed, he was for many years the common resource for Mr. Flamsteed, Sir Jonas Moore, Dr. Halley, and others, in all sorts of troublesome and delicate calculations, Mr. Sharp continued all his life a bachelor, and spent his time as recluse asa hermit. He was of a middle stature, but very thin, being” of a weakly constitution; he was remarkably feeble the last three or four years before he died,. which was on the eighteenth of July, 1742, in the ninety-first year of his age. In his retirement at Little Horton, he em ployed four or five rooms or apartments in his’ house for different purposes, into which: none of his family could po ibly enter at any time’ without his permi ion. He was seldom visited’ by any persons, except two gentlemen at Bradford, the one a mathematician, and the other an ingenious apothecary: these were admitted when he chose to be seen by them, by the signal of rubbing a stone against a certain part of the outside wall of the house. He duly a trended the di enting chapel at Bradford, of which he was a member, every Sunday. At these times” he took care to he proyided with plenty of half pence, which he very charitably suffered to be taken singly out of his hand, held behind him during his walk to the chapel, by a number of poor people who followed him, without his ever looking back, or asking a single question. Mr. Sharp was very irregular as to his meals, and remarkably sparing in his diet, which he frequently took in the following manner: a little square hole, something like a window, made a communication between the room where he was usually employed in calculations, and another chamber or rvom in the house, where a servant could enter; and before this hole he had contrived a sliding board: the _ servant always placed his victuals in this hole, without speaking or making the least noise, and when he had a little leisure he visited his cupboard to see what it aflorded to satisfy his hunger or thirst. But it often happened that the breakfast, dinner, and supper have re- _mained untouched by him when the servant has gone to remove what was left, so deeply engaged had he been in calculations. Cavities might easily be perceived in an old English oak table where he sat to write, by the frequent rubbing and wearing ef his elbows. Gutta cavet lapidem, . By Mr. Sharp’s epitaph it appears that he was related to archbishop Sharp; and Mr. Sharp, the eminent surgeon, who some years since retired from busine , is the nephew of our author. Another nephew was the father of the late Mr. Ramsden, the celebrated instrument-maker, who said that his grand uncle Abraham, our author, was some time, in his younger days, an exciseman, which occupation he eithd on coming to a patrimonial estate of about two hundred pounds a year, For more particulars respecting this extraordinary man, see Dr. Hutton’s Mathematical Dictionary, vol. ii. SHaRv (Thomas), D. D. younger son of Dr. John Sharp, was born in Yorkshire, and educated at Trinity college, Cambridge. His obtained the rectory of Rothbury, North umber land, a prebend of Durham, and the archdeaconry of North umber land, and died 1758, aged 65. He is author of two di ertations on the etymology of the Hebrew words Elohim and Berith, 8vo.—besides discourses on the antiquity of the Hebrew tongue and characters, . He was father to Granville Sharp, known as an elegant cla ical scholar. -SHARPE (Gregory), D. D.F.R.A.S.S. of Yorkshire, 1713, came from Hull school to Westminster, and then went to Aberdeen. He was minister of Broadway chapel, St. James’s, and chaplain to the king, and master of the Temple. He died 1771. He wrote a review of the controversy about the demoniacs of the new testament, Svo.—two di ertations on the origin of language, and the power of letters, with a Hebrew lexicon, 8vo.—defence of Dr. Clarke against Leibnitz, 8vo.—di ertation on the origin and structure of the Latin tongue, Svo. . To Suarp. v. a. (from the noun.) To make keen (Ben Jonson). 660 661