It is easily seen that, in the process of determining the masscentre, any group of particles may be replaced by a single particle whose mass isequal to that of the group, situate at the mass-centre of the group.
In historic times it was situate on the lower slopes of the hills, Coressus and Prion, which rise out of a fertile plain near the mouth of the river Cayster, while the temple and precinct of Artemis or Diana, to the fame of which the town owed much of its celebrity, were in the plain itself, E.N.E.
He calls Aga Mahommed chief of Mazandaran, as also of Astarabad and some districts situate in Khurasan, and describes his tribe the Kajar, to be, like the Indian Rajput, usually devoted to the profession of arms. Whatever hold his father may have had on Gilan, it is certain that this province was not then in the sons possession, for his brother, Jiafir Kuli, governor of Baifrush (Balfroosh), had made a recent incursion into it and driven Hidaiyat Khan, its ruler, from Resht to Enzeli, and Aga Mahommed was himself meditating another attack on the same quarter.
A circlet of radially situate infrabasals (IBB) may also be present.
In the application to mechanics these coefficients are the masses of particles situate at the respective points, and are therefore all positive.