SHARP, (ABRAHAM,) in biography, an eminent mathematician, mechanist, and astronomer, was descended from an an cient family at Little Horton, near Brad ford, in the west riding of Yorkshire, where he was born about 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 practi cal, that he soon 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 business of a mer chant. Upon this he removed to Liver. pool, where he gave himself up wholly to the study of mathematics, astronomy, &c and where for a subsistence, he open ed a school, and taught writing and ac counts, &c.
He had not been long at Livefpool, when he accidentally feel in company with a merchant, or tradesman, visiting that town from London, in whose house it seems the astronomer Flamsteed then lodged. With the view, therefore, of becoming acquainted with this eminent man, Mr. Sharp engaged himself with the merchant as a In consequence he soon contracted an intimate acquaintance and friendship with Mr Flamsteed, by whose interest and recommendation he obtained a more profitable employment in the dock-yard at Chatham, where he continued till his friend and patron, knowing his great merit in astronomy and mechanics, called him to his assistance, in contriving, adapting, and fitting up the astronomical apparatus in the royal obser vatory at Greenwich, which had been lately built, namely, about the year 1676, Mr. Flamsteed being then thirty years of age, and Mr Sharp twenty-five.
In this situation he continued to assist Mr. Flamsteed in making observations (with the mural arch, of eighty inches radius, and 14U 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 time of their transit over the meri dian ; also the diameter of the Sun and Moon, and their eclipses, with those of Jupiter's satellites, the variation of the compass, &c. He assisted him also in
making a catalogue of nearly 3000 fixed stars. as to their longitudes and magni tudes, their right ascensions and polar distances, with the variations of the saute while they change their longitude by one degree.
But from the fatigue of continually ob serving the stars, at night, in a cold thin air, joined to a weakly constitution, lie was reduced to a 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 recove ry, he began to fit up an observatory of his own, having first made an elegant and curious engine for turning all kinds of work in wood or brass, with a maundril for turning irregular figures, as ovals, crosses, wreathed pillars, &c. Beside these, he made himself' most of the tools used by joiners, clock makers, opticians, mathematical instrument-makers, &c. The limbs or arcs of his large equatorial instrument, sextant, quadrant, &c. he gra duated with the nicest accuracy, by dia gonal divisions 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 bands.
It was at this time that he assisted Mr.
Flamsteed, in calculating most of the ta bles in the second volume of his " Histo ria Ccelestis," as appears 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 constella tions visible in our hemisphere, with the still more excellent drawings of the plani spheres, both of the northern and south ern constellations. And though these drawings of the constellations were sent to be engraved at Amsterdam by a mas terly hand, yet the originals far exceed. .d the engravings in point of beauty and elegance ; these were published by Mr. Flamsteed, and both copies may be seen at Horton.