Encourages RP in his speculations about the nebulae and the structure of the Milky Way, which RP suggested is formed of a 'system of convolutions,' but raises objections to RP's views. Discusses idea that the Milky Way contains miniatures of itself and that beyond it may be a hierarchy of universes comparable to the Milky Way.

Elaborates on his hypothesis that all forms of nebulae are part of the Milky Way and on his 'twisted-stream theory' of the Milky Way's structure. Favors view that dark matter is relatively common in space and that it extinguishes light from distant objects. Proposes method of measuring stellar diameters.

Discusses Olbers's Paradox, raises objections to RP's argument for the existence of dark celestial matter, and points out problems in RP's method of measuring stellar diameters.

Accepts JH's objection to his method of measuring stellar diameters. Quotes an argument he had published suggesting the existence of a hierarchy of systems in an infinite universe. Discusses his studies of the relation of proper motions to the sun's motion. Asks JH's permission to publish JH's idea that some nebulae may be 'miniature' of the Milky Way.