—— 
RAIN-GAUGE, 
14 
ing of the monsoons; and while they last, the 
winds are always veering.—The annual quantity 
of rain is greatest at the equator, and gradually 
diminishes as we approach the pole. This will 
be evident from the following table, showing the 
annual depth of rain in different latitudes. 
Lat. N. Fall of Rain. 
Grenada, 12° 126 inches. 
Cape Frangois, 19° 46’ 120) copes 
Calcutta, DPKe) ORY Sipe. 
Rome, . 41° 54’ he) G0 
England, FDO 1 GES) > Blo 
Petersburg, 59° 16’ Gia. 
Uleaborg, 63° 1 Spe = 69 
Gn the contrary, the number of rainy days is 
smallest at the equator, and increases in propor- 
' tion to the distance from it. From north lati- 
|| tude 12° to 43° the mean number of rainy days 
|| is 78. 
From 43° to 46° the mean number is 103 
66 462 66 502 66 66 66 6é 134 
66 502 66 602 66 66 66 66 161 
| Hence it is obvious that the rain falls in very 
heavy showers in warm climates, and that it be- 
comes more and more gentle as we advance to- 
wards the pole. Consequently, in hot climates, 
the air must be much less loaded with moisture, 
and the rate of evaporation much greater than 
in cold climates. For when rain falls very heavy, 
a great portion of it runs off by the surface, and 
flows into the sea. But this happens to a much 
less extent when the fall of rain is more gentle. 
RAIN-GAUGE, or Piuviometer. A machine 
for measuring the quantity of rain that falls. 
There are various kinds of rain-gauges: one of 
the best is 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 in- 
strument 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 cylinder, 
and cause the cork to float; and the quantity of 
water in the cylinder may be seen by the height 
to which the stem of the tloat is raised. The 
stem of the float is so graduated as to show, by 
its divisions, the number of perpendicular inches 
of water which fell on the surface of the earth 
since the last observation. It is hardly necessary 
to observe that, after every observation, the cylin- 
der must be emptied. A very simple rain-guage, 
and one which answers all practical purposes, 
consists of a copper funnel, the area of whose 
opening is exactly ten square inches. This fun- 
nel is fixed in a bottle, and the quantity of rain 
caught is ascertained by multiplying the weight 
in ounces by 173, which gives the depth in inches 
and parts of an inch. In fixing these gauges, 
care must be taken that the rain may have free 
access to them. Hence the tops of buildings are 
usually the best places. When quantities of rain, 
collected in them at different places, are com- 
pared, the instruments ought to be fixed at the 
same heights above the ground at both places, 
RAKE. 
because, at different heights, the quantities are 
always different, even at the same place. 
RAJANIA. A genus of tropical plants, of the 
yam family. Three species, all summer-blooming 
climbers, with herbaceous coloured flowers, and 
varying in height from 7 to 24 feet, have been 
introduced to Britain; but are interesting only 
to botanists. The name was formed in honour 
of the distinguished British naturalist Ray. 
RAKE. A toothed implement for gathering 
hay, gleaning stubbles, pulverizing small beds of 
soil, covering small garden seeds, and several 
other kindred purposes. 
The corn-rake varies in size and structure in 
different counties; but, in most cases, is a more 
or less simple drag-implement with iron teeth. 
“The head of the corn-rake,” says an article in 
the Quarterly Journal of Agriculture on Reaping 
with the Scythe, “should be made of fine ash as 
light as possible, but strong enough to bear the 
driving in of a number of iron teeth; and it 
should be at least 5 feet in length, and feruled 
with iron at both ends. The teeth should be 7 
inches in length, and 4 inches apart, and so 
curved at their point as that the weight of the 
rake may rest upon the curve, with their points 
free of the ground, when the rake is held ina 
working position. The points of the teeth should 
be thin and broad. The shank of the rake may 
be of light fir, and fully 6 feet in length. An iron 
rod passing from the shank on each side to the 
head, will prevent the latter being twisted out of | 
its post. A short handle, like the left handle of — 
the scythe, and fastened at a convenient spot on | 
the shank with an iron wedge, will facilitate the 
passage of the rake over the ground.” 
“The drag-rake, in its simplest form,” says 
Mr. Ransome, “ is merely a long cross head, with 
a row of teeth placed in it; in some these are 
straight ; they are, however, generally bent, with | 
their points projecting forward. A very excel- | 
lent and light implement, having the teeth of | 
steel, and made with screws, so as to admit of | 
being easily replaced in case of accident, is well © 
known as Badgley’s improved drag-rake. These 
rakes have, from time to time, increased in length 
and weight, till they became too large to be bal- 
anced by the hand. Two small wooden wheels 
were then added, which rendered them manage- 
able by women or boys. Further addition hav- 
ing been made to them, they are now sufficiently 
strong to be worked by ahorse. Used on fallows 
when foul, to remove the couch grass, they act 
as a harrow, to get together the rubbish, or 
in harvest time they act as a rake to collect 
the loose corn which may have escaped from 
the scythe or sickle. In order to clear them 
readily, there are different contrivances; one of 
the most simple and efficient of which is such, 
that by lifting the handle the teeth are brought 
between two iron bars, which constitute part of 
the frame, by which means all the rubbish is 
stripped off from the teeth of the rake.” 
