RAI 
seen of this fish weighing fifty and even eighty 
pounds. It commonly lies in forty fathom 
water, and is supposed to stupify its prey 
by this extraordinary facultj'. It is some- 
times nearly imbedded in the sands of shal- 
lows, and is stated, in these cases to give to 
any one who happens to tread upon it, an 
astonishing and overwhelming shock. On 
dissection, it was found to exhibit no mate- 
rial difference from the general structure of 
the ray, excepting with respect to tlie elec- 
tric or galvanic organs, which have been 
minutely examined and detailed by the ce- 
lebrated anatomist, John Hunter. He 
states them “ to be placed on each side of 
the cranium and gills, reaching thence to 
each great fin, and extending longitudinally 
from the anterior extremity of the animal 
to the transverse cartilage which divides 
tlie thorax from the abdomen.” From the 
whole description, it appears, that these or- 
gans, as Mr. Shaw observes, constitutes a 
pair of galvanic batteries, disposed in the 
form of perpendicular hexagonal columns ; 
while, in the gymnotus electricus, the gal- 
vanic battery is disposed lengthwise on the 
lower part of the animal. It is stated, that 
the torpedo, in its dying state, communi- 
cates shocks in more than usually rapid suc- 
cession, but in proportional weakness,. and 
in seven minutes, in these circumstances, 
three hundred and sixty small shocks were 
distinctly felt. On the same authority (that 
of Spallanzani) it is reported, that the 
yonng torpedo can exercise this power at 
the moment after its birth, and even pos- 
sesses it while a feetus, several of these liav. 
ing been taken from the parent fish, and 
been found to communicate perceivable 
shocks, which, however, were more dis- 
tinctly felt when these animals were insu- 
lated on a plate of glass. 
RA JANIA, in botany, so named in me- 
mory of John Ray, our celebrated natu- 
ralist ; a genus of the Dioecia Hexandria 
class and order. Natural order of Sarmen- 
taceee. Asparagi, Jussieu. Essential cha- 
racter: calyx six-parted ; corolla none : fe- 
male, styles three ; germ inferior, three- 
celled, with tw’o of the cells obliterated ; 
seed one, with one wing. There are seven 
species ; these are climbing plants, by 
means of the stem twisting towards the 
left ; the root is tuberous ; the flowers in 
axillary spikes or racemes. They are all 
natives of the West Indies. 
RAIL, in architecture, is used in differ- 
ent senses, as for those pieces of timber 
which he horizontally between the pannels 
RAI 
of wainscot ; for those which lie over and 
under the balusters in balconies, staircases, 
and the like ; and also for those pieces of 
timber which lie horizontally from post to 
post in fences, either with poles or with- 
out. 
Rail, (see Rallus) ortygometra, in or- 
nithology, a genus of birds of the order 
of Gralloe, the beak of which is shorter 
than the toes : it is of a compressed form, 
and terminated in a point; but the two 
chaps are equal in length. It is of the size 
of the common magpie, and is an elegant 
bird, of a bright-brown colour, variegated 
with black spots; it is common in rich pas- 
tures, where its constant note is crex, crex. 
RAIN. See Meteorology. 
RAiNgaugc, a machine for measuring the 
quantity of rain that falls. There are va- 
rious kinds of rain-gauges : that used at the 
apartments belonging to the Royal Society 
at Somerset-house, is thus dercribed. The 
vessel which receives the rain is a conical 
funnel, strengthened at the top by a brass 
ring twelve inches in diameter. The sides 
of the funnel, and inner lip of the brass 
ring, are inclined to the horizon in an angle 
of more than 65°, and the outer lip is an 
angle of more than 50°, which are such de- 
grees of steepness, that there seems no pro- 
bability either that any rain which falls 
within the funnel, or on the inner lip of the 
ring, shall dash out, or that which falls on 
the outer lip shall dash into the funnel. 
Plate XIII. Misc. fig. 9, represents one of 
the best construction of rain-gauges. It con- 
sists of a hollow cylinder, having within it a 
cork-ball attached to a wooden stem, which 
passes through a small opening at the top, 
on which is placed a large funnel. When 
this instrument is placed in the open air in 
a free place, the rain that falls within the 
circumference of the funnel will run down 
into the tube, and cause the cork to float ; 
and the quantity of water in the tube may 
be seen by the height to which the stem of 
the float is raised. The stem of the float is 
so gladnated, as to show by its divisions 
the number of perpendicular inches of wa- 
ter which fell on the surface of the earth 
since the last observation. It is hardly ne- 
cessary to observe, that after every obser- 
vation the cylinder must be emptied. 
A very simple rain-gauge,, and one which 
will answer all practical purposes, consists of 
a copper funnel, the area of whose opening 
is exactly ten square inches : this funnel is 
fixed in a bottle, and the quantity of rain 
caught is ascertained by multiplying the 
