HOL 
Hold fast, a large piece of iron, in tlie 
shape of the letter S, fixed into a wall 
to strengthen it. Also a tool used by join- 
ers, carvers, &c. which goes through their 
benches to hold fast such work as cannot be 
finished by its being held in the hand. 
HOLLAND, in commerce, a fine and 
close kind of linen, so called from its be- 
ing first manufactured in Holland. 
HOLLOA, in sea language, an excla- 
mation of answer to any person who calls 
to another to ask some question, or to give 
a particular order : thus, when the master 
means to give any order to the people in 
the main-top, he previously calls “ Main- 
top hoay,” to which they answer, “ Holloa,” 
to shew that they hear him and are ready. 
It is also the answer in hailing a ship at a 
distance.. See Hailing. 
HOLLOW square, in the military art, a 
body of foot drawn up, with an empty 
space in the middle for colours, drums, and 
bagsage. 
HOLLY. See Ilex. 
HOLOMETER, a mathematical instru- 
ment that serves universally for taking all 
measures, both on the earth and in the 
heavens. 
HOLORACEjE, in botany, the name of 
the twelfth order in Linnaeus’s “ Fragments 
of a Natural Method,” consisting of pot herbs, 
or plants used for the table, and entering . 
into the economy of domestic affairs. This 
order is separated into two divisions. 
1. Hermaphrodite plants. 2. Male, female, 
androgynous, and polygamous plants. This 
order contains trees, shrubs, and perennial 
and annual herbs ; some of the woody vege- 
tables, as the bay, retain their green leaves 
during, the winter ; the roots are long ; the 
stems and young branches are cylindric. 
In the greatest part of the aquatic plants of 
this order, the stalks are hollow within ; the 
buds are of a conical form ; the leaves are 
generally simple, alternate, entire, and at- 
tached to the branches by a cylindric foot- 
stalk, which is sometimes very long, but 
generally short. 
HOLOSTEUM, in botany, a genus of 
the Triandria Trigynia class and order. 
Natural order of Caryophyllei. Essential 
character : calyx five-leaved ; petals five ; 
capsule one-celled, subcylindrical, opening 
at top. There are five species. 
HOLOTHURIA, in natural history, a 
genus of the Vermes Mollusca class and or- 
der. Body detached, cylindrical, thick, 
naked, and open at the extremity ; mouth 
surrounded by fleshy branched tentacula or 
H O M 
feelers. These are all inhabitants of the 
sea, and expand or contract themselves at 
pleasure ; the anterior aperture serves them 
both as a mouth and vent, and from the 
hinder one they reject waters which had 
been previously drawn in ; the tentacula are 
retractile. There are twenty-three species. 
H. pentactes, or five rowed Holothuria, is 
noticed by Pennant. It has an incurvated 
cylindric body, marked with longitudinal 
rows of papillae. ; out of the centre of each 
issue, at pleasure, slender feelers like the 
horns of snails ; the upper extremity retrac- 
tile ; when exerted it assumes a cordated 
form, surrounded at the apex with eight 
tentacula, elegantly ramified, of a yellow 
and silver colour. It is found on the shores 
near Penzance. H. trenmla is a foot long, 
inhabits the Mediterranean and Adriatic 
seas ; the body is cylindrical when extended, 
and oblong when contracted ; it is various 
in colour, but generally of a beautiful mix- 
ture of red and white ; the cylindrical tubes 
beneath the body act as so many suckers, 
by which the animal fixes itself firmly to the 
bottom of the sea. Another curious spe- 
cies noticed by Gmelin is H. denudata, is 
oblong, with interrupted lateral lines, and 
without a crest or tail, inhabits the Ame- 
rican ocean. It is three or four inches 
long, with a body slowly tapering at both 
ends, transparent, of a firm gelatinous con- 
sistence and hollow, opening by a small 
triangular aperture next the crest, and a 
narrow round one at the other extremity ; 
they have a spiral milky line down the 
back, under this another larger opaque one, 
and on each side below these another 
smaller purple one. They are sometimes 
found single, and frequently sticking length- 
ways together. The word holothuria is 
used by Pliny and Aristotle ; but Mr. Pen- 
nant supposes they both intended, under 
this name, to describe those marine bodies 
now denominated zoophyta. Aristotle, how- 
ever, seems to have admitted that they pos- 
sessed animal life, a circumstance that has 
in modern times been completely ascer- 
tained. \ 
HOMALIUM, in botany, a genus of the 
Polyandria Trigynia class and order. Na- 
tural order of Rosace®, Jussieu. Essential 
character : calyx six or seven parted ; co- 
rolla six or seven petalled; stamens twenty- 
one, in three bodies ; pericarpium one- 
celled, many-seeded. There are two spe- . 
cies.- 
HOMER, Omer, Cords, or Chomer, 
in Jewish antiquities, a measure containing 
