156 



Abhandlungen tier Kbnigl. Akademie der Wissenschaften zu 



Berlin, aus dem Jahre 1845. 4to. — By the Academy. 

 Bericht iiber die zur Bekanntmachung geeigneten Verhandlungen der 



Konigl., Preuss. Akademie der Wissenschaften zu Berlin. 



Juli — December 1846, und Januar — Juni 1847. 4to. — By 



the Academy. 

 Bemerkungen iiber Gyps und Karstenit, von J. F. L. Hausmann. 



4to. — By the Author. 

 Nachrichten von der Georg-Augusts-Universitat und der Konigl. 



Gesellschaft der Wissenschaften zu Gottingen. 1846. — By the 



Society. 

 Tradescant der Aeltere 1618 in Russland. Von Dr J. Hamel. 



4to. — -By the Author. 

 Annuaire Magnetique et Meteorologique du Corps des Ingenieurs 



des Mines de Russie, ou Recueil d'Observations Magnetiques et 



Meteorologiques, par A. T. Kupffer. Annee 1844. Nos. 1 



& 2. — By the Editor. 

 An Engraving of the late Principal B-obertson. — By John Russell, 



Esq. 



Monday, 3d January 1848. 

 Right Rev. BISHOP TERROT, V.P., in the Chair. 

 The following communication was read : — 



1. On Algebraical Symbolism. By Bishop Terrot. 



The author commenced by proving the propriety of the adoption 

 of the minus sign for quantities of an affection opposite to those 

 affected by the plus sign, and detecting the limits within which this 

 use of the absolute minus was reasonable and effective. 



He observed that this was merely a particular case of the nota- 



tion which symbolizes the inclination of lines by the factor 1" '^, 

 namely, the case where 5 = 180^, and proceeded to shew within what 

 limits the algebraical rules for the treatment of exponential quanti- 

 ties are applicable to the symbols of inclined lines. 



After referring to the use of this notation in all the problems of 

 plane Trigonometry, especially those which treat of the sines and 

 cosines of multiple arcs, he gave some examples of its applicability 



