VOL. IV.] PHILOSOPHICAL TRANSACTIONS. 32f 



middle of the globe manifestly appearing both above and below beyond the oval 

 of his anses; which was hardly discernible the last year. The inclination of the 

 great diameter of the oval to the equator was measured several ways, and was 

 found of about 9 degrees, although at that time it should be only of 4 degrees, 

 according to what M. Huygens has affirmed in his system of Saturn, viz. that 

 the plane ojf the ring which environs the globe of this planet is inclined to the 

 plane of the ecliptic but 13° 30'. But from this, and other more exact obser- 

 vations, M. Huygens finds that, instead of 23° 30', the angle of the planes of the 

 ring and of the ecliptic must be about 31° ; and that not only the shape which 

 Saturn has at present, but also all those that have been noted since the true 

 ones were observed, do perfectly agree with the hypothesis of the ring ; and par- 

 ticularly that of July l664, which was made and published by Sig. Campani, 

 wherein the great diameter is double the less. See fig. 3. pi. 9. 



Extract of M. de la Quintiny's Letter, concerning his Way of ordering 

 Melons; now communicated for the satisfaction of several curious 

 Melonists in England. N" 45, p. 901, 



Observ^ations now of no manner of use. 



An Account of two Boohs. N"" 45, p. 903. 



I. Renati Franc. Slusii* Mesolabum. Seu duae medi^ Proportionales inter 

 extremas datas per Circulum et per Infinitas Hyperbolas vel Ellipses, et per 

 quamlibet exhibitae. Ac Problematum omnium Solidorum efFectio per easdem 



the degrees of the French meridian, which have since been carried on both to greater extent and with 

 more accuracy, by tlie Cassinis, also by Mechain and Delambrej and he died in l682 or l683. His 

 works are chiefly as follow: 1. A Treatise of Levelling j 2. Practical Dialling, by calculation; 3. 

 Fragments of Dioptrics; 4. Experiments on Running Water; 5. Of Measurements; 6. Mensuration 

 of Fluids and Solids; 7. Abridgement of the Measure of the Earth; 8. Journey to Uraniburg, or As- 

 tronomical Observations made in Denmark; 9- Astronomical Observations made in different parts of 

 France; 10. The Connoissance des Temps, from l679 to l683. All these, and some other tracts, 

 are to be found in the 6th and 7th volumes of the Memoirs of the Academy of Sciences. 



' * Rene Francis Walter Slusius, or Sluse, was born in l622 at Vise> in the county of Liege, 

 where he enjoyed honours and preferment. He became abbe of Amas and canon of Liege; and ac- 

 quired great celebrity by his knowledge in mathematics and physics. The Royal Society elected him 

 one of their members, and inserted several of his compositions in the volumes of tlieir Transactions : 

 viz. Method of drawing Tangents to all Geometrical Curves, in vol. 7; Demonstration of the same, 

 in vol. 8; and a paper on the Optic Angle of Alhazen, also in vol. 8. There were also published 

 some learned letters of his, besides the Mesolabium et Problemata Solida, above described. This 

 learned and ingenious man died at Liege in l685, at 63 years of age. 



