August 20. 
THE COTTAGE GARDENER. 
313 
The White variety have just the reverse of plumage, the 
holy being of a snowy white and the crest black. They are 
almost extinct with us, but I have heard are plentiful in 
Egypt. I have never seen hut four specimens, the last, a 
very old hen, at St. Omer. 
The Spangled are divided into two sub varieties, termed 
Gold or Silver ; the golden being a reddish-brown, and the 
silver a creamy-white; either of these mixed with black 
constitutes the ground colour, all the feathers being tipped 
with white, whence the term Spangled. (Since, however, 
they have become so very scarce, many other fowls, of quite 
different markings, haye, improperly I consider, been called 
Spangles.) 
Polands, from what information I can gain, appear to 
have been brought by the Spaniards from the East, by 
them taken into the Netherlands, and thence we have 
received them. Seal good Poles are very scarce; dealers, 
through ignorance or otherwise, continually selling Ham- 
burghs or mongrels for the pure breed, and prizes are 
sometimes given for birds as Poles which I should call 
Hamburghs, a description of which is necessary to guard 
persons against deception. 
Hamburghs come from Germany, many coming direct 
from Hamburgh, from which circumstance they derive their 
name. They are tufted like the Pole, but the tuft is 
smaller, does not come so forward, and, consequently, leaves 
the eyes more exposed, and is fronted by a small comb of 
curious shape, generally consisting of a very small double 
comb, terminating in two sprouts or horns ; they are desti¬ 
tute of the white spangles and white in the tuft; their 
colour is gold or silver, plieasanted, that is, the feathers of 
gold or silver are edged with a glossy black, resembling the 
breast feathers of a cock pheasant, and giving the bird 
a dotted or scaly appearauce; they are also sometimes 
muffled, and are considered good layers. In my opinion 
they owe their origin to a cross between the Pole and the 
Dutch Every-day-layer, though some say they can't, or, 
perhaps, won't, see any difference. 
These, and innumerable crosses between them and Poles, 
are plentiful, and are generally sold as Poles. I hope I 
have said sufficient to make it plain to those willing to 
learn, that there is a difference, and unless Pole fanciers 
are more particular, I fear Poles will become quite extinct 
before long, which is much to be regretted, as Poles are not 
only a beautiful variety, but first-rate layers, and excellent, 
for the table. If agreeable, I will describe the Dutch Every- 
day-layer at a future time.—B. P. Bbent, Bose Cottage, 
Bessels Green, Scvenoaks. 
[We shall be obliged by any additional communication.— 
Ed. C. G.] 
MASON'S HYGROMETER. 
At page 233, of the present volume, I notice, that in answer 
to a correspondent, you say, “ we cannot learn anything about 
Mason's Hygrometer.” Allow me to inform you that it is 
founded on the principle of ascertaining the amount of 
vapour in the air, by noticing the degree of cold produced 
by evaporation. The method was first devised by Dr. 
Hutton. What title it has to be called “ Mason’s Hygrome¬ 
ter ” I know not. It is a method of hygrometry that has 
been recently adopted by all meteorologists, and is usually 
designated by them as the “Wet and Dry Bulb.” The 
instrument consists of two sensitive thermometers placed 
side by side; round the bulb of one a piece of fine muslin 
is tied with lamp cotton, and the ends of the cotton allowed 
to hang in a small vessel of water, which is suspended near 
them; the muslin is thus kept wet by capillary attraction ; 
and the degree of cold being observed, which is called the 
temperature of evaporation, and compared with the tempe¬ 
rature of the air, which is indicated by the dry bulb thermo¬ 
meter, the degree of humidity, the dew point, &c., are found 
by means of tables constructed for that purpose. These 
tables are to be had for half-a-crown, together with a de¬ 
scription of the use of the wet and dry bulb thermometer, 
at Taylor’s, Bed Lion Court, Fleet-street; they are com¬ 
piled by James Glaisher, Esq., Meteorological Observer at 
Greenwich. • 
The rationale of the instrument is best itnderstood in 
this way. If wo consider what would take place when the 
air is saturated with moisture—in this case the dry bulb 
thermometer would indicate exactly the same as that 
covered with the wet muslin. This state of things is often 
observed in a fog, or at night; but as the air becomes less 
moist, it will be easily conceived that the dry bulb ther¬ 
mometer will rise above the other—thus showing how far 
the air falls short of complete moist saturation. Tables 
are necessary to ascertain the exact amount of vapour in 
the air, because the capacity of the air for moisture varies 
with its temperature ; but let no reader be dismayed at the 
idea of tables, they are no more formidable” than the 
columns of a ready reckoner, which are just what the said 
tables are in hygrometry instead of £ s. d. 
Tho instruments that are sold by the best makers for 
accurate meteorological observations are expensive; but, as 
I think, in these days, no one who pretends to scientific 
gardening ought to be without the means of telling, by some 
surer indicator than his bodily feelings, the state of the air 
which his plants enjoy (or suffer ), I shall state, as briefly as 
I can, how this kind of hygrometer can be made at a 
moderate expense. 
As every greenhouse, or place for plants, has one ther¬ 
mometer already, the extra expense incurred, in order to 
have this useful instrument, is only that of another ther¬ 
mometer. The companion thermometers should correspond 
as accurately as possible in different parts of the scale, and 
should be selected on this principle. The comparison will 
be best effected by placing them in water about 90° Fahren¬ 
heit, and allowing them to remain in the water whilst it 
gradually cools. It will be easily ascertained then, out of a 
number, which pairs are the fittest associates. The ordi¬ 
nary thermometer with the box-wood scale must then be 
prepared, by cutting off so much at the bottom of the scale 
as will allow the bulb to project beyond it at least half-an- 
inch. The tubes, of course, must be taken out whilst the 
operation is performed: let the two then be fastened side 
by side to a small board, about three inches apart; the 
lower edge of the board should not come below the scales. 
It is essential to accuracy that the bulbs should be left thus 
free, on all sides, to the air, and to protect the thermometer 
from breaking, let the board be fixed in a frame which 
should reach at least three inches below the bulbs. The 
frame should be not less than two inches deep from back to 
front, and the thermometers, on their board, should be fixed 
half-way between the back and front. One of the thermo¬ 
meters may then be prepared by tying a piece of muslin 
neatly round its bulb witli a thread of lamp cotton, and the 
ends of the cotton dipped in a small glass suspended from 
the side of the frame ; the surface of the water in the 
glass should be about even with the bulb, or a little 
below it. If above it, the bulb will be flooded, and the 
result of the observation will be false. The muslin should 
be just so wet as to moisten the finger when applied to it. 
The cotton will act better if previously soaked in a solution 
of soda. 
I wish I could persuade all gardeners to set to work with 
these instruments; they are nearly all-hut necessary for 
the regulation of greenhouses and hothouses, and out-of- 
doors. I feel sure that many striking and useful truths 
might be recorded of the varying degrees of humidity of the 
air, in contact witli different soils, at the different seasons. 
Every gardener is something of a meteorologist per force, 
and I would have him an intelligent one, not trusting to the 
indications of his bodily feelings, but those of scientific 
instruments, many of which are now so cheap as to be 
within reach of almost every one ; and very large proprietors 
might well insist on a register of meteorological phenomena 
being kept, which, in due time, might become of great value 
to science.—S igma. 
ON CLASS FORTY AT THE BIRMINGHAM 
POULTRY SHOW. 
Class 40, at the Birmingham and Midland Counties Exhi¬ 
bition of Poultry in 1851 (Class 4(i of 1852), will be remem¬ 
bered by lovers of rare and curious specimens, as offering 
prizes (the catalogue having previously enumerated all well- 
known sorts) “ for any other distinct variety.” It is to be 
