to 



RAMSDEN, JESSE. 



RAMUS, PETER. 



the general belief respecting it being that Ramsay had written the 

 Voyages of Cyrus in English as well as in French. The best edition 

 of the French is that of ' Paris et Londres,' 2 vols. 8vo, 1727. The 

 work however for which posterity is most indebted to him is that 

 entitled ' L'Histoire de la Vie de Francois da Salignac de la Motte 

 Fe'ne'lou,' Hague, 1723 ; published also in London the same year. His 

 great intimacy with Fdnelon has made us acquainted with many 

 interesting facts of his private life, and it contains a valuable record 

 of his opinions. His other published writings are 1. ' Discours sur 

 le Poeine Epique,' originally forming the preface of his edition of 

 Telemachus, in 1717. 2. ' Essai Philosophique sur le Qouvernement 

 Civil,' London, 1721 ; it was afterwards reprinted under the title 

 ' Essai de Politique.' 3. ' Histoire de Turenne,' Paris, 1735, 2 vols. 

 8vo, and 4 vols. 12mo. With some affectation in the style, and a 

 redundancy of reflections, this history possesses much merit from the 

 precision of its facts and the lively portraiture of its characters. 4. 

 ' Le Psychometre, ou Reflexions sur les diffe'rens Caracteres de 1' Esprit, 

 par uu My lord Anglais.' 5. A posthumous work published at Glasgow 

 in 1749, 2 vols. 12mo, in English, entitled ' Philosophical Principles of 

 Natural and Revealed Religion explained and unfolded in a Geometrical 

 Order.' 



RAMSDEN, JESSE, was born at Salterhebble, near Halifax, York- 

 shire, 1735. He was the son of an innkeeper. When nine years old 

 he was admitted into the free grammar-school of Halifax ; and after 

 attending there for about three years, he was placed under the pro- 

 tection of an uncle, who resided in the north of Yorkshire. By him 

 lie was sent to a school conducted by Mr. Hall, a clergyman, who was 

 in repute as a teacher of the mathematics, and under whom he attained 

 to some proficiency in geometry and algebra. His studies were inter- 

 rupted by his father apprenticing hiui to a cloth worker at Halifax. 



At the age of twenty we find him engaged as a clerk in a cloth 

 warehouse in London, in which capacity he continued till 1757-58, 

 when his predilection for other pursuits led him to bind himself for 

 four years to a working mathematical and philosophical instrument 

 maker, named Barton, in Denmark Court, Strand. Upon the comple- 

 tion of his term, he engaged himself as assistant to a workman, named 

 Cole, at a salary of twelve shillings a week ; but this connection was 

 of short duration. He then commenced working on his own account, 

 and his skill as an engraver and divider gradually recommended him 

 to the employ of .the leading instrument makers, more particularly 

 Nairue, Sisson, Adams, and Dollond. Ramsden subsequently married 

 Dollond's daughter, and he received with her a part of Mr. Dollond's 

 patent right in achromatic telescopes. His occupation afforded him 

 frequent opportunities of observing the defective construction of the 

 sextants then in use, the indications of which, as had been pointed 

 out by Lalande, could not be relied on within five minutes of a degree, 

 and might therefore leave a doubt in the determination of the longi- 

 tude amounting to fifty nautical leagues. The improvements intro- 

 duced by Ramsden are said by Piazzi to have reduced the limits of 

 error to thirty seconds. (' Account of the Life and Labours of Rams- 

 den ' in a Letter addressed to Lalande, and published by him in 

 'Journal des Sc.avans,' November 1788, p. 744.) This circumstance, 

 added to the cheapness of his instruments, which were sold for about 

 two-thirds the price charged by other makers, soon produced a demand 

 which, even with the assistance of numerous hands, he found difficulty 

 in supplying. In his workshops the principle of the division of labour 

 was carried out to a considerable extent, and a proportionate dexterity 

 was acquired by the workmen ; but it is asserted that in none of these, 

 even the most subordinate, and least of all in the higher departments, 

 did the skill of the workmen surpass that of Ramsden himself. His 

 attention was incessantly directed to new improvements and further 

 simplification, the result of which was the invention of a dividing- 

 machine, for the graduation of mathematical and astronomical instru- 

 ments. The date of this invention is prior to the year 1766. At first 

 it had many imperfections ; but by repeated efforts of ingenuity 

 throughout a period of ten years they were successfully removed. In 

 1777 it was brought under the notice of the Commissioners of the 

 Board of Longitude, by Dr. Shepherd, and by them a premium of 

 61 51. was paid to the author, upon his engaging to divide ' sextants at 

 six, and octants at three shillings, for other mathematical instrument 

 makers.' A description of the machine was immediately published, 

 by order of the Board, under the supervision of Dr. Maskelyue ( Lond., 

 1777, 4to.), and was shortly after translated into French by Lalande. 

 A duplicate of the machine itself is said to have been purchased by 

 the president, Bochard de Saron, and introduced into France concealed 

 in the support of a table made for that purpose. (Weiss, ' Biog. 

 Univers.') As early as 1788 no less than 983 sextants and octants 

 had issued from Rainsdeu's workshop. In 1799 the description of 

 another machine constiucted by Ramsden for dividing straight lines 

 by means of a screw was also published by order of the Board : but 

 this invention does not appear to have been of much practical use. 

 It was however in the construction of many of a larger class of astro- 

 nomical instruments that Ramsden acquired most reputation, though 

 they were probably least productive of pecuniary gain. The theodolite 

 employed by General Roy in the English Survey was made by 

 Ramsden, and no instrument of the kind that had been previously 

 made would bear comparison with it. A similar remark is applicable 

 to the equatorial constructed for Sir George Schuckburgh, which was 



also the largest that had then been attempted. Ramsden took out a 

 patent for his new equatorial, and a description of it was published by 

 the Hon. Stewart Mackenzie, brother to the Earl of Bute ; but his 

 inventive genius seldom permitted him to construct two instruments 

 alike. Hia telescopes, erected at the observatories of Blenheim, 

 Mannheim, Dublin, Paris, and Gotha, were remarkable for the supe- 

 riority of their object-glasses ; and in his mural quadrants, furnished 

 to the observatories of Padua and Vilna, Dr. Maskelyne was unable to 

 detect an error amounting to two seconds and a half, a degree of 

 accuracy which was then a matter of admiration among astronomers. 

 Ramsden however always recommended that the mural quadrant 

 should be superseded by a mural circle ; and the circles erected in the 

 observatories of Palermo and Dublin, the first of which was of five 

 and the latter of twelve feet diameter, were constructed by him in 

 accordance with this recommendation. 



Among Ramsden's minor inventions and improvements may be 

 enumerated his catoptric and dioptric micrometers (described in the 

 'Phil. Trans.,' 1779), the former of which was an improvement upon 

 that of Bougier ; optigraph ; dynamometer (for measuring the magni- 

 fying powers of telescopes); barometer; electrical machine; mano- 

 meter ; assay-balance ; level ; pyrometer ; and the method introduced 

 by him for correcting the aberrations of sphericity and refrangibility 

 in compound eye-glasses. (' Phil. Trans.,' 1783.) 



Ramsden was elected a fellow of the Royal Society in 1786. In 

 1794 a similar compliment was paid him by the Imperial Academy of 

 St. Petersburg ; and the following year the Copley medal was awarded 

 to him by the Royal Society, in testimony of the importance of 'his 

 various inventions. By this time his health had become much impaired 

 by his ardent devotion to his profession. In 1800 he was advised to 

 visit Brighton, where he died, on the 5th of November of that year. 

 From 1766 to 1774 his shop and residence was in the Haymavket; but 

 in the latter year he removed to Piccadilly, where his business con- 

 tinued to be conducted after his decease. 



In his habits we are told that he was temperate to abstemiousness, 

 and that for many years he restricted himself to very few hours of 

 repose. Most of the time that he could spare from the immediate 

 duties of his profession was devoted to the perusal of the works of 

 science and literature. His memory was remarkably retentive, and at 

 an advanced age he made himself sufficiently master of the French 

 language to read Moliere and Boileau. The fortune of which he died 

 possessed was not considerable, and a large portion of it was directed 

 by his will to be distributed among his workmen. 



RAMUS, PETER (PIERRE DE LA RAMEE), was born in a 

 village in Picardy, in 1502 according to one account, and in 1515 

 according to another. His parents were extremely poor, and the future 

 philosopher was set when a boy to tend sheep. Disgusted with this 

 employment, he ran away from his parents to Paris. After some time, 

 and after he had encountered much misery, one of his uncles offered 

 some pecuniary assistance, and Rarnus now entered the College of 

 Navarre as a servant. He made great progress in all studies, with 

 very little assistance from masters. At the completion of his course, 

 when he presented himself for the degree of master of arts, he under- 

 took as an exercise what then seemed the almost impious task of 

 showing that Aristotle was not infallible. The exercise was adjudged 

 successful, and Rarnus henceforth devoted himself to the study of the 

 works of Aristotle as to the object of his life. In 1543 he published 

 his new system of logic, with strictures on the logic of Aristotle. The 

 publication of this work exposed him to great obloquy. He was 

 charged with impiety and sedition, and with a desire to overthrow 

 all science and religion through the medium of an attack on Aristotle. 

 On the report of an irregular tribunal appointed to consider the charges 

 made against him, the king ordered his works to be suppressed, and 

 forbade his teaching or writing against Aristotle on pain of corporal 

 punishment. Ramus now turned to the study of mathematics, and to 

 prepare an edition of Euclid. Shortly afterwards he began a course of 

 lectures on rhetoric at the College of Presles, the plague having driven 

 away numbers of students from Paris. He was named principal of 

 this college, and the Sorbonne ineffectually endeavoured to eject him 

 on the ground of the royal prohibitory decree. This decree was 

 cancelled in 1545 through the influence of the Cardinal de Lorraine, 

 to whom he had dedicated his edition of Euclid. He now began a 

 course of mathematics in Paris. In 1551 he was named by the king 

 (Henri II.) professor of philosophy and eloquence in the College of 

 France. During the next ten years he published a Greek, Latin, and 

 French grammar, and several treatises on mathematics, logic, and 

 rhetoric. Rarnus had embraced Protestantism, and now shortly again 

 brought upon himself great trouble by the zeal with which he advo- 

 cated the new doctrines. Charles IX. offered him an asylum at 

 Fontainebleau ; but, while he was absent from home, his house was 

 pillaged and his library destroyed. He returned to Paris in 1563, and 

 resumed possession of his royal chair. Civil troubles again drove him 

 away from Paris, and in 1568 he asked permission to travel. He went 

 to Germany, and was received everywhere with honour. He gave 

 lectures on mathematics at Heidelberg, and while in this town he 

 made public profession of Protestantism. Shortly after his return to 

 Paris he fell a victim in the massacre of St. Bartholomew. 



Although Ramus had many merits as a philosopher, and did much 

 good by his opposition to the Aristotelian philosophy which then 



