It is stated by Rosalind Lutece in the Voxophone A City, Suspended that she had trapped an atom in mid-air and that it simply failed to fall. This description would seem to indicate that the Lutece particle can be set to maintain a specific altitude, and the effects of gravity are countered or do not affect the particle, and it can impart that effect to things attached to it. The particle's attributes must be able to be changed since craft such as The First Lady, gunships and even the city's buildings are able to move in all three dimensions and do so with some speed. Control of the Lutece Particle does not seem to be perfect or has some limitation. The First Lady uses conventional engines to move, the gunboats use thrusters for maneuvering, and the buildings have balloons trimming them. I