Definition of "tenour"

Our political ſyſtem is placed in a juſt correſpondence and ſymmetry with the order of the world, and with the mode of exiſtence decreed to a permanent body compoſed of tranſitory parts; wherein, by the diſpoſition of a ſtupendous wiſdom, moulding together the great myſterious incorporation of the human race, the whole, at one time, is never old, or middle-aged, or young, but in a condition of unchangeable conſtancy, moves on through the varied tenour of perpetual decay, fall, renovation, and progreſſion.

1790, Edmund Burke, Reflections on the Revolution in France, 5th edition, page 48

It is the conſciouſneſs of this merited approbation and eſteem which is alone capable of ſupporting the agent in this tenour of conduct.

1790, Adam Smith, “Of the Beauty which the Appearance of Utility Bestows upon the Charactes and Actions of Men; Creech, and J. Bell & Co., part IV, page 481

Mr. Gooch was so far moved from the even tenour, to buy—first a pocket-book, containing a small view of Rotheles Castle, at the top of a neatly-ruled page for memoranda; and, secondly, a number of a work, illustrating the principal gentlemen's seats in England, and containing a large view of the said castle.

1838 (date written), L[etitia] E[lizabeth] L[andon], chapter XIV, in Lady Anne Granard; or, Keeping up Appearances. […], volume I, London: Henry Colburn, […], published 1842, page 181