If we submit our rectangular system to “deformation,” on simple and recognised lines, altering, for instance, the direction of the axes, the ratio of x ⁄ y , or substituting for x and y some more complicated expressions, then we shall obtain a new system of co-ordinates, whose deformation from the original type the inscribed figure will precisely follow.
— from On Growth and Form by D'Arcy Wentworth Thompson

In the still more elongated skull of such a form as the Indian Gavial, the whole skull has undergone a great longitudinal extension, or, in other words, the ratio of x ⁄ y is greatly diminished; and this extension is not uniform, but is at a maximum in the region of the nasal and maxillary bones.
— from On Growth and Form by D'Arcy Wentworth Thompson

As the spirit of aggrandizement, which is said to have 199 actuated the public and private conduct of Monsieur T—— has been so much talked of, it may, perhaps, excite some surprise, when it is mentioned that several persons who know him well, some of whom esteem him, and with some of whom he is not a favourite, declare, notwithstanding the anecdotes related of X Y, and Monsieur Beaucoup d'Argent, in the american prints, that they consider him to be a man, whose mind is raised above the influence of corruption.
— from The Stranger in France or, a Tour from Devonshire to Paris Illustrated by Engravings in Aqua Tint of Sketches Taken on the Spot. by Carr, John, Sir

Of the twelve who had 107 made my little company in the “sangar” we erected on the first ridge of X. Y. Z. beach, there was not one left.
— from The Big Fight (Gallipoli to the Somme) by David Fallon

For instance, when I asked them for the result of x + y × x - y , they were obliged to make the sum [ 216 ] and could not supply the result offhand.
— from Armenia, Travels and Studies (Volume 2 of 2) The Turkish Provinces by H. F. B. (Harry Finnis Blosse) Lynch