Hecatonstylon, Hecatonstyle, Gr. and R. (ἑκατὸν and στῦλος). A portico or colonnade with a hundred columns.
Hecte or Hectæus, Gr. = a sixth (R. modius). In dry measure, the sixth part of the medimnus, or nearly two gallons English. Coins of uncertain value bore the same name; they were sixths of other units of value.
Hegira (Arabic hajara, to desert). The flight from Mecca, 16th July, A. D. 622, from which Mohammedan chronology is calculated.
Helciarius, R. One who tows a boat. He was so called because he passed a rope round his body in the way of a belt, the rope thus forming a noose (helcium).
Helepolis, Gr. and R. (ἑλέ-πολις, the taker of cities). A lofty square tower, on wheels, used in besieging fortified places. It was ninety cubits high and forty wide; inside were nine stories, the lower containing machines for throwing great stones; the middle, large catapults for throwing spears; and the highest other machines. It was manned with 200 soldiers. The name was afterwards applied to other siege engines of similar construction.
Helical, Arch. (ἕλιξ, a wreath). A spiral line distinguished from spiral. A staircase is helical when the steps wind round a cylindrical newel; whereas the spiral winds round a cone, and is constantly narrowing its axis. The term is applied to the volutes of a Corinthian capital. (See Helix.)
Heliochromy (Gr. ἥλιος, the sun, and χρῶμα, colour). Process of taking coloured photographs.
Heliopolites, Egyp. One of the nomes or divisions of Lower Egypt, capital An, the sacred name for Heliopolis near Cairo.
Heliotrope. The Hæmatite or blood-stone; a siliceous mineral of a dark green colour, commonly variegated with bright red spots.
Heliotropion, Gr. A kind of sun-dial. (See Horologium.)