Definition of "verticality"

For these complicated reasons, although, when the sun is vertical, and darts a perpendicular ray, it is supposed to strike with greatest force; yet, in those countries where it is vertical twice a year, in passing to and from the Tropic of Cancer, the greatest heat is not during the instant of its verticalities, but some weeks after, when it is returning from one Tropic to the other, and its rays oblique.

1774, Edward Long, The History of Jamaica‎, London: T. Lowndes, Volume III, Book III, Chapter VII, Section X, p. 655

A tendency to direct verticality, placing itself in, perhaps, violent contrast with the Romanesque horizontalism of the Anglo-Norman, had been in the Early English Gothick, the special characteristick of that beautiful style.

1847, Raphael Brandon and Joshua Arthur Brandon, An Analysis of Gothick Architecture, London: P. Richardson, Introduction, pp. 2-3

From their garden, a precarious terrace in a world of verticality, we could look down two or three thousand feet into the Teesta Valley below, an inky well imprisoning a fleet of porcelain clouds.

1933, Robert Byron, First Russia, Then Tibet‎, Part II, Chapter 3