98 
Proceedings of the 
The following Donations to the Library were announced : — 
A Treatise on Electricity in Theory and Practice. By Aug. De la 
Rive. Translated for the Author by Charles Y. Walker, E.R.8. 
London, 1858. 8vo. Yol. III.— -.From the Author, 
Journal of the Statistical Society, March 1858. — From the Society . 
The American Journal of Science and Art. January 1858. 8vo. 
— From the Editors. 
Transactions of the Royal Scottish Society of Arts. Yol. Y. Part 1, 
Edinburgh, 1857, 8vo. — From the Society. 
Memorie della Accademia delle Scienze dell’ Institute di Bologna. 
Tomo VII. Bologna, 1857, 4to. — From the Academy. 
Proceedings of the Royal Astronomical Society. Yol. XVIII. No. 
4.- — From the Society. 
Proceedings of the Royal Society of London. Vol. IX. No. 29.— 
From the Society . 
Map of England and Wales, showing the Path of the Centre of the 
Moon’s Shadow on the 15th March 1858.- — From H. F. 
Talbot , Esq . 
Monday , 5th April 1858, 
The Right Rev. Bishop TERROT in the Chair. 
The following Communications were read : — 
1. On the Facets an<5 Corners of Flat-Faced Solids. By 
Edward Sang, Esq F.R.S.E. 
In this paper it was shown that the usually received theorems 
concerning the faces of polyhedrons are true only of one class of solids. 
The theorem that <£ no solid can have every one of its faces more 
than pentagonal ” was contradicted by the exhibition of a solid 
bounded entirely by hexagons. Each corner of this solid is trihedral, 
and the sum of all its angles amounts to four times as many right 
angles as there are corners ; whereas the usual theorem is, that 
“ the angles of any solid amount to four times as many right angles 
as there are corners , less eight.” The number of uniformal solids, 
that is of solids of which all the faces have the same number of 
sides, and all the corners the same number of angles, instead of 
being five, was shown to be indefinite by the exhibition of the solid 
