by a secret dose. What an idea must it give us of the spirit of party to find so horrid a perfidy rendered meritorious by it! There is no reason, however, to suppose that he had any title to this piece of merit, nor indeed that the report was propagated with his concurrence, for he has himself given a very particular account of Cromwell's last illness, which contains the clearest evidence that poison had not the least share in his death. Dr. Bate died April 19, 1669, and was buried at Kingston upon Thames.

This physician was author of a famous historical and political Work in Latin, intituled, "Elenchus motuum nuperorum in Anglia, simul ac Juris regii ac Parliamentarii brevis enarratio." Part I. printed in 1640: Part II. in 1661. This has in general been accounted one of the fairest and most impartial relations of those unhappy transactions, and is written in a very elegant style. A third part was added to it by Dr. Skynner. He likewise wrote, "The Royal Apology, or Declaration of the Commons in Parliament, Feb. 11, 1647." Printed 1648. With regard to his services to his own profession, the share he had in Dr. Glisson's treatise" de Rachitide" has been mentioned in a late publication. He published nothing else; but after his death Mr. James Shipton, apothecary, printed first in 1688, a Dispensatory, entitled "Pharmacopoeia Bateana," consisting of a great number of Recipes, chiefly taken from Dr. Bates's private practice. This was translated into English by Salmon, with many additions of his own, and came into great vogue. Like most other works of this nature, it contains many good and many trifling remedies.

1781, Sept.

XIX. Biographical Memoirs of ABRAHAM SHARP.

MR. URBAN,

SEND you some memoirs of Mr. Abraham Sharp, a man truly eminent, though unnoticed by any of our biographical writers. What relates to the first twenty-five years of his age, I learned from his friend the mathematician, at Bradford, mentioned in the memoirs, and some few others, about forty years ago. And though I never had any per sonal knowledge of Mr. Sharp, nevertheless, soon after his

* Aikin's Biographical Memoirs of Medicine in Great Britain,

death I had frequent opportunities of looking over his curious mathematical instruments, manuscripts, drawings, &c. &c. which are now mostly dispersed and sold. I have long wished to see his life written by some abler hand, or by some intimate friend or acquaintance, who could do justice to his memory, but I believe they are all dead.

Yours, &c.

G. G.

Mr. Abraham Sharp, an eminent mathematician, mechanic, and astronomer, was descended from an ancient family at Little Horton, near Bradford, in the West Riding of Yorkshire*. At a proper age he was put apprentice to a merchant at Manchester; but his genius and disposition became so remarkable for the study of the mathematics, not only in the practical, but also in the speculative parts, that he soon became uneasy in that situation of life. By the mutual consent therefore of his master and himself (though not perhaps altogether with that of his father) he quitted his employ of a merchant, and removed to Liverpool; where, according to the most natural bent of his genius, he gave himself up wholly to the study of the mathematics, astronomy, &c. and likewise opened a school, and taught writing, accompts, &c.

He did not continue long at Liverpool before he accidentally fell in company with a London merchant or tradesman, under whose roof the famous astronomer Mr. Flamsteed lived; and, that he might be personally acquainted with that eminent man, he soon after left Liverpool, and engaged with the above merchant in the capacity of a book-keeper. It was here that he first contracted an intimate friendship and acquaintance with Mr. Flamsteed, by whose interest and recommendation he obtained a more lucrative employ than that of a book-keeper, in the dock-yard at Chatham, where he continued till his friend and patron (knowing his great merit and abilities in astronomy and mechanics) called him to his assistance in contriving, adapting, and fitting up the astronomical apparatus, in the Royal Observatory at Greenwich, now called Flamsteed-house, which had then been lately built, about the year 1676; Mr. Flamsteed being at that time 30 years of age, and Mr. Sharp 25.

In this situation he continued to assist Mr. Flamsteed in

He was related, as appears from his epitaph, to Archbishop Sharp. VOL. IV.

H

making observations (with the mural arch of near 7 feet radius, and 140 degrees on the limb) of the meridional zenith distances of the fixed stars, sun, moon, and the other planets, with the times of their transits over the meridian; together with observations of the sun and moon's diameters, eclipses of the sun, moon, and Jupiter's satel lites, variations of the compass, &c. He likewise assisted him in taking a catalogue of the right ascensions, distances from the pole, longitude and magnitudes of near 3000 fixed stars, with variations of their right ascensions and distances from the pole, whilst they change the longitudes one degree.

But from a continual observance of the stars at night, in a cold thin air, joined to a weakly constitution, he 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 upon 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 in wood or brass, with a mandrel for turning irregular figures, as ovals, roses, wreathed pillars, &c. &c. besides which he made himself most of the tools used by joiners, clockmakers, opticians, and mathematical instrument-makers. The limbs of his large equatorial instrument, sextant, quadrant, &c. he graduated with the nicest accuracy, by diagonal 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 hands.

It was at this time that he assisted Mr. Flamsteed in calculating most of the tables in the second volume of his "Historia Coelestis," as appears by their letters to be seen at Horton; likewise the curious drawings of the charts of all the constellations visible in our hemisphere, together 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 exceed 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 his elaborate treatise of "Geometry Improved by a large and accurate table of segments of circles, its construction and various uses in the solution of several difficult problems,

* I believe contrived and graduated by Mr. Sharp.

with compendious tables for finding a true proportional part; and their use in these or any other tables exemplified in making logarithms or natural numbers from them to sixty places or figures;" there being a table of them for all primes to 1100 true to 61 figures.

Likewise his concise treatise of Polyedra, or solid bodies of many bases, both the regular and others: to which are added, twelve new ones, with various methods of forming them, and their exact dimensions in surds, and in numbers. Illustrated with variety of copper-plates, neatly engraved by his own hands. Also the models of these Polyedra he cut out in a most amazing exact manner in box-wood.

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, his sextant, quadrants of various sorts, dials; also in a curious armillary sphere, which, besides the common properties, has moveable circles, &c. for exhibiting and solving all spherical triangles: also his double sector, &c. &c. all contrived, graduated, and finished, in an elegant manner, by himself. In short, he had a remarkable clear head for contriving, and an extraordinary hand for executing, any thing, not only in mechanics, but likewise in drawing, writing, and making the most exact and beautiful schemes or figures in all his calculations 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, whereby the truth thereof is proved to 72 figures; all which may be seen in Sherwin's tables; that is, if the diameter of a circle be 1, the circumference thereof will be found equal to 3,141592653589793238462643383279502884197169399375105820974944592307816405

26, &c.

He also calculated the logarithmetic sines, tangents, and secants of the seconds to every minute of the first degree of the quadrant, which laborious investigation most probably may be seen among the curiosities of the Royal Society, as they were presented to the Rev. Patrick Murdoch for that purpose; in which manuscript may be seen his very neat and exact manner of writing and arranging his figures, not to be equalled by the best penman now living. In the same manuscript may be seen the logarithmetic sines, tangents, &c. to every second of the first minute of the quadrant, all calculated by the indefatigable Mr. Sharp.

He kept 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, &c. 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 (a large chest full) from these and many other celebrated mathematicians, it is evident, that Mr. Sharp spared neither pains nor time to promote real science. He was a bachelor, of a middle stature, but very thin, being of a weakly constitution, and was quite superannuated three or four years before he died, which was on the 18th of July, 1742, in the 91st year of his age.

He engaged or employed four or five different rooms or apartments in his house for different purposes, into which none of his family could possibly enter at any time without his permission. He was visited rarely by any, except two gentlemen of Bradford, the one a mathematician, and the other an ingenious apothecary: these were admitted by the signal of rubbing a stone against a certain part of the outside of the house. He duly attended the dissenting chapel at Bradford, of which he was a member, every Sunday, at which time he took care to be provided with plenty of halfpence, 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 at 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 generally employed in calculations, and another chamber or room in the house where a servant could enter; and before this said hole, he had contrived a board or a slide; 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 afforded to satisfy his hunger or thirst. But it often happened, that the breakfast, dinner, and supper have remained untouched by him, when the servant has gone to remove what was leftso deeply engaged had he been in calculations*.

Cavities might easily be perceived in an old English oak

* A similar story is told of Sir Isaac Newton. EDIT