Hornbeam Hornbeam Hornbeams are hardwood trees in the flowering plant genus "Carpinus" in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere. The common English name "hornbeam" derives from the hardness of the woods (likened to "horn") and the Old English "beam" "tree" (cognate with German "Baum"). The "American hornbeam" is also occasionally known as "blue-beech", "ironwood", or "musclewood", the first from the resemblance of the bark to that of the American beech "Fagus grandifolia", the other two from the hardness of the wood and the muscular appearance of the trunk, respectively.
Northern celestial hemisphere Northern celestial hemisphere The northern celestial hemisphere, also called the Northern Sky, is the northern half of the celestial sphere; that is, it lies north of the celestial equator. This arbitrary sphere appears to rotate westward around a polar axis due to Earth's rotation. At any given time, the entire Northern Sky is visible from the geographic North Pole, while less of this hemisphere is visible the further south the observer is located. The southern counterpart is the southern celestial hemisphere. In the context of astronomical discussions or writing about celestial cartography, this celestial hemisphere may also simply then be