[146] In these two houses are Jesuits of other nations. They are stiled Portuguese, because these houses and churches depend on the mission of the Jesuits founded by the king of Portugal.

[147] There are beaten there the five watches of the night. The sound is heard thro’ the whole city.

[148] Yong lo, emperor of the last dynasty Ming, built these two towers.

[149] The tribunals of the ministers and grand masters of the emperor’s house are in the inclosure Tse kin.

[150] The feet are different in China; but 1800 feet always make a ly. According to the measure of the foot the ly will be greater or less.

[151] This power is called in China the dynasty Leao.

[152] There is extant, in the Chinese and Tartar Mantcheou languages, an history of the dynasty of Ki tan.

[153] Of which dynasty there is extant a very curious history.

[154] Book I. Part ii. Prop. 3. Experiment 8. of his Optics.

[155] If α, β, γ, δ, &c. be supposed to represent the co-sines of the angles 360° ⁄ n, 2 × 360° ⁄ n, 3 × 360° ⁄ n, &c. (the radius being unity); then the roots of the equation zⁿ - 1 = 0 (expressing the several values of p, q, r, s, &c.) will be truly defined by 1, α + √αα - 1, α - √αα - 1, β + √ββ - 1, β - √ββ - 1, &c. The demonstration of this will be given farther on.