ON THE HISTORY OF MECHANICS. 189 



ship with Fust and Schaeffer, is the first that is universally allowed to 

 have practised the art.* It was introduced into this country by William 

 Caxton. 



Leonardo da Vinci, the most accomplished man of his age, was born 

 about the year 1443, and excelled not only in painting and poetry, but 

 also in architecture, mathematics, and mechanics. The state of practical 

 mechanics in this and the subsequent centuries may be estimated from 

 Ramelli's collection of machines, which contains several curious and 

 useful inventions ; some of them long since forgotten, and even lately 

 proposed again as new. 



The works of Bacon, Lord Verulam, although not immediately tending 

 to the advancement of mathematics or of mechanics, are universally allowed 

 to have conduced very materially to the improvement of every branch of 

 science, by the introduction of a correct and conclusive method of philo- 

 sophical argument and inquiry. Guido Ubaldi published, in 1577, a 

 treatise on mechanics, not wholly exempt from inaccuracies, and in the 

 following year a valuable commentary on the works of Archimedes : some 

 of the properties of projectiles were about the same time rather imagined 

 than demonstrated by Tartalea : Benedetti soon after began to reason 

 correctly respecting the principles of mechanics ; but it was reserved for 

 Galileo to lay the foundations of the discoveries, which have succeeded 

 each other with increasing rapidity for more than two centuries. He 

 investigated, in the year 1589, the laws of accelerating forces, and showed 

 the nature of the curve which is described by a projectile ; he inferred from 

 observation the isochronism of the vibrations of a pendulum, and the 

 principle was soon after applied by Sanctorius to the regulation of time- 

 keepers. Stevinus, a Dutchman, was the first that clearly stated the 

 important law by which the equilibrium of any three forces is determined ; 

 and the properties of the centre of gravity were successively investigated by 

 Lucas Valerius, Lafaille, and Guldinus, who made some additions to 

 the elegant propositions of Archimedes which relate to it.t 



The application of the more intricate parts of the mathematics, to prac- 

 tical purposes of all kinds, has become incomparably easier and more 

 convenient since the invention of logarithms. This important improvement 

 was made by Baron Napier ; his tables were published in 1614 : J and they 

 were reduced to a still more useful form by the labours of Briggs and 

 of Gunter.|| Descartes, about the same time, was making considerable 



* Fischer sur les Monumens Typographiques de Gutenberg, 4to, Mentz, 1802. 



f The authors here mentioned occupy a prominent position in the History of Me- 

 chanics. We therefore add a list of their principal works. Lord Bacon's Works, 

 a new edition by Basil Montagu, 14 vols. 1825-31. Guido Ubaldi Mechanicorum 

 liber, fol. Pesaro. Tartalea Nuova Scienza, 4to, Venice, 1537. Quesiti et Inventi 

 Diversi, 1544. Benedettus Diversarum Speculationum liber, fol. Taurini, 1585. 

 Galileo Opera, 4 vols. Padova, 1744. See Lect. IV. Stevinus, Beghinselen der 

 Waagconst, 1586. (Euvres Mathematiques, 2 vols. fol.. Ley de. 1634. Lucas Va- 

 lerius, DeCentro Gravitate Solidorum, 4to, Romse, 1604. Lafaille, Theoremata de 

 Centre Gravitatis, 4to, Antwerp, 1632. Guldinus de Centro Gravitatis, fol. 

 Vienna;, 1635. 



J Mirifici Logarithmorum Canonis Descriptio, 4to, Edinb. 1614. 



Arithmetica Logarithmica, fol. Lond. 1624. 



|| Works, 4to, 1 680. The tables of logarithms in common use are, Taylor's, 

 Collet's, Hutton's, and Babbage's. 



