The relation of the Thomas precession to Ishlinskii's theorem as applied to the rotating image of a relativistically moving body

It is shown that, for a solid body following a relativistic curvilinear pat h (Thomson precession), its rotation angle is numerically equal to the rest -frame-observed solid angle through which the body-fixed axis turns as a co nsequence of the rotation change the body image undergoes due to Lorentz le ngth contraction and the retardation of the light emitted by various portio n of the body. In classical mechanics the same relation connects the body r otation angle to the actual solid angle the body-fixed axis subtends as the body performs a conical motion - which is a consequence of Ishlinskii's th eorem.