The study of these vital phenomena is greatly facilitated by the conception of the field of diffusion and poles of diffusion, and of the lines of force, which are the Trajectories of the molecules of the solutes, and the particles and globules in suspension.
"The Mechanism of Life"
Stéphane Leduc
Keeping the car high enough to be above the Trajectories of incoming shells, Harry Quong circled over the city while Hassan Bogdanoff talked to Gongonk Island on the radio.
"Uller Uprising"
Henry Beam Piper, John D. Clark and John F. Carr
These hairy orbs that appear in all directions, and whose Trajectories are sometimes actually perpendicular to the plane of the ecliptic, appear to obey no regular law.
"Astronomy for Amateurs"
Camille Flammarion