hammer-beam 
the roofing, it does not act as a tie ; it is essentially a 
lever, as is shown in the figure. Here the inner end of 
Hammer-beam Roof, Westminster Hall, London. 
A, A, Hammer-beams. 
the hammer -beam, A , receives the weight of the upper part 
of the roof, which is balanced by the pressure of the prin- 
cipal at its outer end. 
hammer-blow (ham'er-blo), n. The blow of a 
hammer, or a blow resembling that of a ham- 
mer, as the impact of an unbalanced wheel. 
The so-called hammer -Wow in locomotives is the ir- 
regularity of the pressure exerted between the wheel and 
rail, which arises from the vertically-unbalanced action of 
the counter- weights placed in the wheel to neutralize the 
horizontal action of the piston and other moving parts. 
Jour. Franklin Inst., CXXIII. 42. 
hammer-cap (ham'er-kap), . A cover for the 
cock of a gun. 
hammer-catcher (ham'er-kach'er), M. In pi- 
anoforte-making, the padded shoulder which 
catches the hammer on its return after strik- 
ing the string. 
hammer-cloth (ham'er-kldth), n. [The earli- 
est form, hamer-cloth, is quoted from the time 
of Queen Mary; said to be "so called from the 
old practice of carrying a hammer, nails, etc., 
in a pocket hid by this cloth" (Webster). 
Others think the orig. form was "hamper-cloth. 
Skeat takes hammer- to be a corruption or an 
E. adaptation of the D. word kernel, canopy, a 
tester, covering, quoting "den kernel van een 
koetse, the seeling [ceiling] of a coach" (Hex- 
am), "the testern of a coach" (Sewel): see 
under heaven.] The cloth which covers the 
driver's seat in some kinds of carriage, usually 
falling in plaits on all four sides. See cut un- 
der coach. 
Hamer-clotheg, with our arms and badges of our colours, 
and all other things apperteininge unto the same wagon. 
Quoted in Arckceologia, XVI. 91. 
hammer-dressed (ham'er-drest), a. Dressed 
or prepared with a hammer: especially applied 
to a building-stone which has been dressed with 
a pointed hammer or pick. 
hammerer (ham'er-er), n. 1. One who works 
with a hammer. 
The till was for many years looked upon as a deposit 
destitute of all traces of life, and only a few hammererg 
continued, Micawber-like, to hope for something turning 
np. Geikie, Ice Age, p. 198. 
2. The three-wattled bell-bird of Costa Rica, 
Chasmorhyitchus tricarunculatus. 
hammer-fish (ham'er-fish), n. The hammer- 
head, or hammer-headed shark. Also called 
balance-fish. 
hammer-harden (ham'er-har // dn), v. t. To 
harden, as a metal, by hammering it while 
cold. 
hammerhead (ham'er-hed), . 1. A shark of 
the family Sphyrnidce or Zygcenidce : so called 
from the great lateral expansion of the head. 
Hammerhead (Sfhyrna ssygaHd). 
There are 3 genera and 6 species, inhabiting most seas. 
The common species Is Sphyrna zyyoena, better known as 
Zygaina malleus, a cosmopolitan species which attains a 
length of from 12 to 15 feet. Those with the head less ham- 
mer-like belong to the genus Reniceps, and are commonly 
called shovelheads. 
2. A catostomine fish, HypenteUum nigricans, 
having a peculiarly shaped head, which is flat 
above and transversely concave between, the 
eyes, while the snout is abruptly turned down. 
It abounds in the fresh waters of the United States, from 
New York to Kansas and Alabama. It sometimes attains 
a length of two feet. Other names are hogsucker, stone- 
roller, and crawl-a-bottom. 
3. The umber or shadow-bird, Scopus umbretta. 
2698 
hammer-headed (ham'er-hed"ed), a. Having 
a head like that of a hammer. Specifically applied in 
zoology (a) to the hammerhead, hammer-fish, or balance- 
fish ; (ft) to an African fruit-bat, Hypeignathug wonxtrosus. 
hammering (ham 'er- ing), n. [Verbal n. of 
hammer 1 , r."] In silversmithing, a dented ap- 
pearance on silverware, each dent being made 
by successive carefully directed blows of the 
hammer. The dents are also sometimes gouged out 
with a tool or pressed in by means of a roll. This mode of 
decoration is of Japanese origin. 
hammerman (ham'er-man), n. ; pi. hammer- 
men (-men). A mechanic whose work involves 
the use of the hammer, as a blacksmith, weapon- 
smith or armorer, goldsmith, etc. 
The smythe contorted the moulder, and the iron smyth 
the hammerman. Bible of 1551, Isn. xli. 7. 
A hard-handed and stiff ignorance worthy a trowel or a 
hammerman. B. Jo-won, Magnetick Lady, ii. 1. 
Visible Ploughmen and Hammermen there have been, 
ever from Cain and Tubalcain downwards. 
Carlyle, Sartor Resartus, p. 118. 
hammer-mark (ham'er-mark), n. A mark left 
by a hammer, as in forging. 
hammer-nail (ham'er-nal), . The pin secur- 
ing the cock to the plate of a flint-lock. It 
is frequently called the lock-nail. Farrow, Mil. 
Encye. 
hammer-oyster (ham'er-ois'ter), n. Same as 
hammer-shell. 
hammer-pick (ham'er-pik), n. A tool having 
a hammer-face at one end of the head and a 
pointed pick at the other; a pick-hammer. 
hammer-pike (ham'er-pik), . A long-shafted 
weapon resembling the war-hammer, it was 
carried in the French army by the subalterns in charge of 
the flag under the first empire (1804-14). Farrow, Mil. 
Encyc. 
hammer-scale (ham'er-skal), n. Same &sforge- 
scale. 
hammer-sedge (ham'er-sej), n. A common Eu- 
ropean sedge, Carex hirta. 
hammer-shell (ham'er-shel), n. A bivalve mol- 
lusk of the pearl-oyster family, Aviculidce, and 
genus Malleus: so 
called from the 
shape of the shell. 
There are several 
species, of Orien- 
tal seas, the best- 
known being Mal- 
leus vulgaris. Al- 
so called hummer- 
oyster. 
hammer-stone 
(ham'er-ston), . 
See flaking-ham- 
mer. 
hammer-tail (ham'er-tal), n. In clockwork, a 
projection extending from the arbor of the rod 
or lever that supports the hammer, on which the 
pins or teeth of a wheel in the striking mecha- 
nism act, as it revolves, to raise the hammer. 
There are three cross bars, . . . which are utilized also 
for carrying cocks for "leading off," for hammer-tail^, 
winding pinions, etc. 
Sir E. Beckett, Clocks and Watches, p. 185. 
hammer-tongs (ham'er-tongz), n. pi. Tongs 
having jaws terminating in pins, used in han- 
dling objects in which holes have been punched, 
such as the heads of hammers and hatchets. 
hammerwise (ham'er-wlz), adv. [< hammer^ + 
-wise."] As if with a hammer. 
One of them saucily snatched off her shoe, and cracked 
them [almonds] hammerwise with the heel. 
Houtellt, Their Wedding Journey, p. 282. 
hammerwort (ham'er-wert), re. [Cf. AS. ham- 
orwyrt, black hellebore, < hamor, hammer, + 
wyrt, wort.] The plant pellitory, Parietaria. 
hammer-wrought (ham'er-rat), a. Worked 
into shape by means of a hammer, as iron : said 
of armor and the like, and also of decorative 
wrought-iron work. 
hammite (ham'It), . Same as ammite. 
hammle, r. i. A dialectal form of hamble. 
hammock 1 (ham 'ok), . [Formerly hamack 
(Sir T. Herbert) or, as Sp., hamaca = P. hamac, 
It. amaca, Pg. maca, OD. hammak, later accom. 
hangmak, hangmat, G. hangmatte, hangmatte (as 
H , mmCT . shcl , (M . Uela 
Sailor's Hammock. 
hamper 
if 'hanging mat'), < Sp. hamaca, a hammock; 
of West Indian origin. Columbus, in the nar- 
rative of his first voyage, says : " A great many 
Indians in canoes came to the ship to-day for 
the purpose of bartering their cotton, and hama- 
cas or nets in which they sleep."] 1. A kind 
of hanging bed. Hammocks used at sea, especially on 
men-of -war, are made of canvas, and have a number of cords 
at each end, called cluex, which are brought together and 
secured to an iron ring, which is hung on a hook attached 
to the deck-beams. Those used in the tropical parts of 
America and in summer in the north are usually formed 
of a network of Panama grass or small cords. 
I ... conducted them into one of the houses, where we 
did presently hang up our hammocks. 
Dampier, Voyages, an. 1688. 
Mrs. Trunnion was out of humour when she found her- 
self under the necessity of being confined with her spouse 
in a hammock. Smollett, Peregrine Pickle, ix. 
O mother, praying God will save 
Thy sailor while thy head is bow'd, 
His heavy-shotted Aamj/ioejfc-shroud 
Drops in his vast and wandering grave. 
Tennyson, In Memoriam, vi. 
2. In entom., the hammock-like sack or case 
carried by the larvre of certain tineid moths, as 
(Ecophora harrisiella, hence called case-hearers. 
If he [P. Huber] took a caterpillar which had completed 
its hammock up to, say, the sixth stage of construction, 
and put it into a hammock completed up only to the third 
stage, the caterpillar simply reperformed the fourth, fifth, 
and sixth stages of construction. 
Daririn, Origin of Species, p. 206. 
To lash a hammock (num.}, to roll a hammock np 
smoothly and pass a lashing round it. To sling a ham- 
mock (>'aiit.\ to fasten in the clues of a hammock and 
get it ready for use. 
hammock 2 (ham'ok), . See hummock. 
hammock-batten ' (ham'ok-bat"n), . A cleat 
or strip of wood used to extend the ends of a 
hammock and keep it spread out. 
hammock-Cloth (ham'ok-kldth), n. Jfaut., a 
canvas tarpaulin covering the hammocks when 
in the nettings to protect them from the wea- 
ther. 
hammock-clues (ham'ok-kloz), n. pi. An ar- 
rangement of small lines at each end of a ham- 
mock by which it is suspended. 
hammock-nettings (harn'ok-nefingz), n. pi. 
Long troughs or boxes constructed on top of 
the bulwarks of the spar-deck in a man-of-war, 
in which the hammocks are stowed during the 
daytime. In former times the hammocks were 
stowed, when not in use, in rope nettings, 
whence the name. 
hammock-rack (ham'ok-rak), . Same as ham- 
mock-nettings. 
hamose, hamous (ha'mos, -mus), a. [< L. ha- 
mus, a hook.] In bot., same as hamate, 3. 
Hampden's case. See case of ship-money, under 
ship-money. 
hamper 1 (ham'per), r. t. [< ME. hamperen, ham- 
pren (rare), hamper, oppress ; origin uncertain ; 
supposed by Skeat to stand for "hameren (the 
p excrescent), another form of ME. hamelen, 
mutilate, E. hamble (where 6 is excrescent); 
but excrescent p would hardly occur in such a 
position ; the reg. form would be 'hambren (cf . 
ME. hamber, yar. of hamer, hammer; E. num- 
ber, etc.), which could hardly change to ham- 
pren; and the senses are too unlike to be im- 
mediately connected. A remoter connection, 
however, may exist; cf. hamble, which is con- 
nected, through OHG. ham (hamm-), mutilated, 
crippled, lame, paralytic, with MHO. hemmen, 
G. hemmen, stop, hinder, check. With hamble, 
cf. North. E. hamel, walk lame, Sc. hammle, 
walk in an ungainly manner, so as to be con- 
stantly in danger of stumbling, Sc. hump, halt 
in walking, stutter, read with difficulty, hamp, 
n., a halt in walking, stuttering; E. dial, ham- 
mer, stammer. Cf . also Sc. hobble, stutter, speak 
or act confusedly; OD. haperen, stutter, hesi- 
tate, D. haperen, falter, hesitate.] 1. To im- 
pede in motion or progress ; render motion or 
progress difficult to; shackle ;, entangle; re- 
strain by force. 
Glad Abram, then, to God gives thanks and praise, 
Vnbindes his Son, and in his room he laies 
A Lamb (there strangely hampered by the head). 
Sylvester, tr. of Du Bartas's Weeks, ii., The Fathers. 
Hem. If he resist, down with him, have no mercy. 
First Boor. I warrant you, we'll hamper him. 
Fletcher, Beggars' Bush, iii. 1. 
Am I over-reach'd ? If there be law, I'll hamper ye. 
Beau, and Ft., Scornful Lady, iii. 2. 
When two substances have different molecular veloci- 
ties at their common surface of mutual contact, the mole- 
cules hamper one another, and energy is lost ; this energy 
takes the form of the energy of electrical displacement. 
A. Daniell, Physics, p. 542. 
