A 



JOURNAL 



OF 



NATURAL PHILOSOPHY, CHEMISTRY, 



AND 



T H E A R T S. 



SUPPLEMENT TO VOL. XXV. 



ARTICLE I. 



An Inquiry^ Gcomctricul and Arithmetical, into certain 

 Properties of Solids in general, and of the Jive regular 

 Bodies in particular. Bjj John Gough, Esq. 



Dkfimtions. I^^.XaN edge of a solid is a line terminated jj^f ^^ 

 by two of its solid angles, and coinraon to two of its adjoin- 

 ing faces. 



JDef. 2tid. From Pappus lib. 5. Ordinate plain figures orDef. 2, 

 polygons are those which are bounded by equal right lines, 

 containing equal angles. 



Def. 3rd. Two or more plain figures arc said to be of theoef. 3, 

 same denomination, when each and all of them are bounded 

 bv the same number of right lines. 



Axioms. Ax. 1st. Three plain surfaces cannot contain Axiom 1, 

 a solid. 



Cor. Hence a pyramid under four triangles is' the simplest Corollary. 

 solid bounded by planes. 



A.v. l7id. Any required solid may be cut out of a given Axiom 2. 

 solid. 



Propositions. Prop. Ist. Let c, t, s, be the number of Prop. V 

 the faces, solid angles, and edges of a solid, bounded by 



Yin.. XXV.— Supplement. Y polygons 



