CRA 
falling over flie top of a chief or otlier ordi- 
nary, so as not to hide but only to be a co- 
vering to it. 
COW, in zoology, the female of the ox- 
kind. See Bos. 
CRAB’S claws. See Materia Me- 
BICA. 
CRAB’S eyes. See Pharmacy. 
Crab, an engine of wood, with threO 
elaws, placed on the ground like a capstan, 
and used at launching, or heaving ships intp 
the dock. 
CRADLE, in surgery, a case in which a 
broken leg is laid after being set. 
CradEe, among shipwri^ts, a timber 
Frame made along the outside of a ship by 
the bilge, for the convenience of launching 
her with ease and safety. 
CRAFT, in the sea-language, signifies all 
manner of nets, lines, hooks, &c. used in 
fishing. Hence all such little vessels as 
ketches, hoys, and smacks, &c. used in the 
fishing trade, are called small craft. 
CRAMBE, in botany, a genus of the 
Tetradynamia Siliquosa class and order. 
Natural order of Siliquosae, Cruciformes. 
Essential character : filaments, the four 
longer, two-cleft at the end, one only of the 
tips bearing an anther ; berry dry, globose, 
deciduous. There are six species, of which 
one is C. maritima, sea-colewoi t ; the roots 
of this plant creep under ground, whereby it 
propagates very fast. The whole plant is 
smooth, glaucus, and sometimes tinged with 
purple ; several stalks arise, about two 
feet high, spreading, much branched, bear- 
ing sessile leaves. The flowers or long pe- 
duncles are white. The fruit at first ovate, 
terminated by the blunt stigma, afterwards 
nearly spherical, the size of large peas. 
The young leaves, covered up with sand, 
and blanched, are boiled and eaten as a 
great delicacy. It is found on the sandy 
and beachy coasts of Sweden and Den- 
mark ; it is also common in many parts of 
England, particularly in the west. 
CRAMP, in medicine, a convulsive con- 
traction of a muscular part of the body, 
being either natural, as in convulsive con- 
stitutions, or accidental, from living in cold 
places, under ground, &c, It affects all 
parts indifferently, but the ham, calves, 
feet, and toes, oftener than the arms and 
hands. 
An effectual preventative for cramp in the 
calves of the legs, whjch is a most grievous 
pain, is to stretch out the heel of the leg as 
fer as possible, at the same time drawing up 
the toes to the body. This will frequently 
CRA 
stop the progress of a fit of the cramp after 
it has commenced ; and a person will, after 
a few times, be able in general to prevent 
the fit coming on, though its approach be 
between sleep and waking. 
CRANE. See Grus. 
CRANE, in mechanics, a machine for 
raising goods into loft, or from vessels to 
wharft, or for lowering them from heights, 
&c. in a safe manner, and by the applica- 
tion of a comparatively small power. Num- 
berless contrivances have been resorted to 
for these puiposes ; the first of them appears 
to have been the great drum-wheel, in which 
one or more men, an ass, &c. being made 
to walk, a rotatory motion followed, where- 
by a rope fastened to the axis of the wheel 
was wound up, and with it whatever weight 
the power thus created was capable of 
lifting. But it was found that various fatal 
accidents attended this piece of machinery ; 
for when the man slipped, the wheel would 
obtain a reverse motion, and by its accu- 
mulated velocity would dash him to pieces. 
On the other hand, if the rope suspending 
the weight gave way, the motion of the 
wheel, it being released from opposition, 
became so accelerated as to produce the 
same fatal effects. 
An improvement upon tiiis was the in- 
clined plane, (seen in fig. 1, PI. IV. Miscel.) 
wliich having ribs, or battens, all pointing 
to its centre, is moved by a man walking 
either nearer to or further from the axis, 
according to the weight to be raised, his 
greatest power being near the edge. The 
rope X, sustaining the weight o, passing 
through the pully y, and winding on the 
axis p, as it revolves in consequence of the 
man’s pressure. To prevent accidents, tlie 
man has hold of the arm n, projecting from 
the post 2 ; so that, in case of a slip, he 
might save himself by bearing tliereon, 
But though this plan is certainly a great 
improvement, yet it cannot be considered 
as altogether safe, and it takes up so much 
space, that it is very rarely in use. The 
windlass,worked by various different powers, 
and those variously applied, has in general 
superseded all other practices, It is to be 
lamented that some are too complex and 
expensive, w’hich would otherwise prove 
highly serviceable. We give that in fig. 2, 
as being cheap and effective. It consists 
merely of a barrel, e, to which three con- 
centric iron wheels, a, b, c, all graduated with 
equidistant teeth, and laying in one plane, 
secured also by cross bars, are affixed. The 
small wheel D having teeth fitting to those 
