JOISTS

, or Joysts, those pieces of timber framed into the girders and summers, and on which the boarding of floors is laid.

“JONES (William), F. R. S. a very eminent mathematician, was born at the foot of Bodavon mountain [Mynydd Bodafon] in the parish of Llanfihangel tre'r Bard, in the Isle of Anglesy, North Wales, in the year 1675. His father's name was John George, his surname being the proper name of his father. For it is a custom in several parts of Wales for the proper name of the father to become the surname of his children. John George the father was commonly called Sion Siors of Llanbabo, to which place he moved, and where his children were brought up. Accordingly our author, whose proper name was William, took the surname of Jones from the proper name of his father, who was a farmer, and of a good family, being descended from Hwfa ap Cynddelw, one of the 15 tribes of North Wales. He gave his two sons the common school education of the country, reading, writing, and accounts, in English, and the Latin Grammar. Harry his second son took to the farming business; but William the eldest, having an extraordinary turn for mathematical studies, determined to try his fortune abroad from a place where the same was but of little service to him. He accordingly came to London, accompanied by a young man, Rowland Williams, afterwards an eminent perfumer in Wych-street. The report in the country is, that Mr. Jones soon got into a merchant's counting house, and so gained the esteem of his master, that he gave him the command of a ship for a West India voyage; and that upon his return he set up a mathematical school, and published his book of Navigation; and that upon the death of the merchant he married his widow: that, lord Macclesfield's son being his pupil, he was made secretary to the chancellor, and one of the deputy tellers of the exchequer:—and they have a story of an Italian wedding which caused great disturbance in lord Macclesfield's family, but was compromised by Mr. Jones; which gave rise to a saying, “that Macclesfield was the making of Jones, and Jones the making of Macclesfield.” The foregoing account of Mr. Jones, I found among the papers of the late Mr. John Robertson, librarian and clerk to the Royal Society, who had been well known to Mr. Jones, and possessed many of his papers.

Mr. Jones having by his industry acquired a competent fortune, lived upon it as a private gentleman for many years, in the latter part of his life, in habits of intimacy with Sir Isaac Newton and others the most eminent mathematicians and philosophers of his time; and died July 3, 1749, at 74 years of age, being one of the vice-presidents of the Royal Society; leaving at his death one daughter, and his widow with child, which proved a son, who is the present Sir William Jones, now one of the judges in India, and highly esteemed for his great abilities, extensive learning, and eminent patriotism.——Mr. Jones's publications are,

1. A new Compendium of the Who'e Art of Navigation, &c; in small 8vo, London, 1702. This is a neat little piece, and dedicated to the Rev. Mr. John Harris, the same I believe who was author of the Lexicon Technicum, or Universal Dictionary of Arts and Sciences, in whose house Mr. Jones says he composed his book.

2. Synopsis Palmariorum Matheseos: Or a New Introduction to the Mathematics, &c; 8vo, London, 1706. Being a very neat and useful compendium of all the mathematical sciences, in about 300 pages.

His papers in the Philos. Trans. are the following:

3. A Compendious Disposition of Equations for exhibiting the relations of Goniometrical Lines; vol. 44, p. 560.|

4. A Tract on Logarithms; vol. 61, pa. 455.

5. Account of the person killed by lightning in Tottenham<*>Court-Chapel, and its effects on the building; vol. 62, pa. 131.

6. Properties of the Conic Sections, deduced by a compendious method; vol. 63, pa. 340.

In all these works of Mr. Jones, a remarkable neatness, brevity, and accuracy, every where prevails. He seemed to delight in a very short and comprehensive mode of expression and arrangement; in so much that sometimes what he has contrived to express in two or three pages, would occupy a little volume in the ordinary style of writing.

Mr. Jones it is said possessed the best mathematical library in England; scarcely any book of that kind but what was there to be found. He had collected also a great quantity of manuscript papers and letters of former mathematicians, which have often proved useful to writers of their lives, &c. After his death, these were dispersed, and fell into different persons hands; many of them, as well as of Mr. Jones's own papers, were possessed by the late Mr. John Robertson, before mentioned, at whose death I purchased a considerable quantity of them. From such collections of these it was that Mr. Jones was enabled to give that first and elegant edition, in 4to, 1711, of several of Newton's papers, that might otherwise have been lost, intitled, Analysis per quantitatum Series, Fluxiones, ac Differentias: cum Enumeratione Linearum Tertii Ordinis.

IONIC Column, or Order, the 3d of the five orders, or columns, of Architecture. The first idea of this order was given by the people of Ionia; who, according to Vitruvius, formed it on the model of a young woman, dressed in her hair, and of an easy elegant shape, as the Doric had been formed on the model of a strong robust man.

This column is a medium between the massive and the more delicate orders, the simple and the rich. It is distinguished from the Composite, by having none of the leaves of acanthus in its capital; and from the Tuscan, Doric, and Corinthian, by the volutes, or rams horns, which adorn its capital; and from the Tuscan and Doric too, by the channels, or fluting, in its shaft.

The height of this column is 18 modules, or 9 diameters of the column taken at the bottom: indeed at first its height was but 16 modules; but, to render it more beautiful than the Doric, its height was augmented by adding a base to it, which was unknown in the Doric. M. le Clerc makes its entablature to be 4 modules and 10 minutes, and its pedestal 6 modules; so that the whole order makes 28 modules 10 minutes.