VOt. XTI,] PHILOSOPHICAL TRANSACTIONS, Ml 



the mercury raised high in the cylinder A, and retired out of B, the spirit of 

 wine will descend into the cylinder B, and the oil of turpentine will fill the tube, 

 so as to make the partition of the two liquors near the cylinder B. But, on 

 the contrary, when the air is light, the mercury will sink in A and rise in B, so 

 as to drive the spirit of wine into the tube, and the oil of turpentine into the 

 cylinder C, so that the section of the 2 liquors will be near C, and the variation 

 of the height of the mercury will be enlarged into almost the length of the 

 tube, without having the counter-pressure from the fluids in the least altered ; 

 the height and weight of the incumbent cylinders being always the same. 



The small alteration that may happen by the dilatation and contraction of the 

 spirit of wine by heat and cold, which ought to be accounted for, may be best 

 discovered by a thermometer hanging by it, containing the same quantity of 

 spirit of wine, and whose tube is, as near as possible, of the same diameter with 

 the tube BC in the barometer, whose descent and ascent must be added and 

 subtracted, to reduce it to a rigorous exactness ; but it is still worth while ta 

 inquire if the mercury itself do not shrink and swell with cpld and heat, so as 

 not to need this correction. 



Le grand et fameux Prehleme de la Quadrature du Cercle resolu Geometri-r 

 quement par le Cercle et la Ligne droite, par M. Mallement de Messange, 

 A Paris, in 12°, 1686. With a Refutation of the same, by M. D. Cluverius, 

 Reg. S.S. N° 185, p. 245. 



This author is one of those unhappy geometricians, who without having 

 acquired a thorough understanding of the principles, have yet thought them- 

 selves able to master the abstrusest difficulties in this nice mathematical science, 

 where the least oversight or mistake subverts the whole superstructure. Hence 

 it is, that the true quadrature of the circle here pretended to, is one of those 

 vain attempts, which the less knowing and more opinionated of their own skill 

 have produced, in this and the last century. 



Voyage de Siam des Peres Jesuites, envoyez par le Roy, aux Indes et a la Chine. 

 A Paris, 1686, 4to. N" 185, p. 249. 



This is a second relation of the voyage and embassy of the French to the 

 King of Siam, in the year l685. The former was composed by Le Chevalier 

 Chaumont, the anibassador, and now this by le Pere Tachart Jesuite, who was 

 one of six fathers of his order, sent with the ambassador, as missionaries to 

 China. These six were mathematicians, and by the king's letters patents were 



VOL. III. y Y 



