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NOTES TO BOOK VI. 



(A.) p. 17- " SIMON STEVIN of Bruges," as he usually 

 designates himself in the title-page of his work, has lately 

 become an object of general interest in his own country, 

 and it has been resolved to erect a statue in honour of him 

 in one of the public places of his native city. He was born 

 in 1548, as I learn from M. Quetelet's notice of him, and 

 died in 1620. Montucla says that he died in 1633; mis- 

 led apparently by the preface to Albert Girard's edition 

 of Stevin's works, which was published in 1634, and which 

 speaks of a death which took place in the preceding year ; 

 but on examination it will be seen that this refers to 

 Girard, not to Stevin. 



I ought to have mentioned, in consideration of the 

 importance of the proposition, that Stevin distinctly states 

 the triangle of forces ; namely, that three forces which act 

 upon a point are in equilibrium when they are parallel and 

 proportional to the three sides of any plane triangle. This 

 includes the principle of the Composition of Statical Forces. 

 Stevin also applies his principle of equilibrium to cordage, 

 pullies, funicular polygons, and especially to the bits of 

 bridles ; a branch of mechanics which he calls Chalinoth- 

 lipsis. 



He has also the merit of having seen very clearly, the 

 distinction of statical and dynamical problems. He re- 

 marks that the question, What force will support a loaded 



