HHalf-hours with the telescopeHalf-hours with the telescopede Richard A. ProctorMateriasAstronomyJuvenile literatureEdiciones (1)Half-hours with the telescope (1873)G. P. Putnam's sons · inglésMás obras de Richard A. ProctorLLessons in elementary astronomyLessons in elementary astronomy1873OOther suns than oursOther suns than ours1887Pleasant ways in science1879