Lord Salisbury and Waddington at the instance of Bismarck, that, when convenient, France should occupy Tunisia, an agreement afterwn.**rds** confirmed (with a reserve as to the eventual attitude of Italy) in despatches exchanged in July and August 1878 between the Quai dOrsay and Downing Street.

Those of them who lived on the outskirts of the pacified territory adopted a mode of life similar to that of their hereditary opponents, and constituted a peculiar class known as Cossacks, living more by flocks and The h e **rds** and by marauding expeditions than by a ri y g p ?'

Since the potential of a small charge of electricity dQ at a distance r is equal to dQ/r, and since the potential of all parts of a conductor is the same in those cases in which the distribution of surface density of electrification is uniform or symmetrical with respect to some point or axis in the conductor, we can calculate the potential by simply summing up terms like **rdS**/r, where dS is an element of surface, o- the surface density of electricity on it, and r the distance from the symmetrical centre.

Then, taking (2/3)**rds** of the cubit, or (1/6)th of the orguia, as a foot, the Greeks arrived at their foot of 12.14; this, though very well known in literature, is but rarely found, and then generally in the form of the cubit, in monumental measures.

Therefore 15.4-16.6; metres = (4/3)**rds** of 12.16 cubed, .

Removing the summation signs in equation (52) in order to restrict its application to two points and dividing by the common time interval during which the respective small displacements ds and ds were made, it becomes Pdsfdt = **Rds**/dt, that is, Pv = Rv, which shows that the force ratio is the inverse of the velocity ratio.

- **Rds** ~ - Rsds+~ - R5ds ~.

In order to produce a retardation from the greater velocity~ v2 to the less velocity Vf, it is necessary to apply to the body a resistance connected with the retardation and the time by an equation identical in every respect with equation (71), except by the substitution of a resistance for an effort; and in overcoming that resistance the body performs work to an amount determined by equation (72), putting **Rds** for Pas..