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THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, February 19, 1861. 
and to let off part of the heat at every second or third joint ? or 
if the draught was too quick for allowing of escape at such joints, 
the mouth of the pipe at the farthest end might be partly closed 
till the escape at all the openings was established. With respect 
to your ash-pit and our own, we prefer a small opening on each 
sjde of the fireplace in front, and case the whole furnace within 
some good non-conducting medium, so as to lose as little heat 
as possible from any part of the apparatus.—D. B.] 
HEAT DECLINED IN A MUSHEOOM-BED. 
The cultivation of the Mushroom having become almost 
universal to the gardener as well as the amateur, I may venture 
to ask a little assistance in the following almost hopeless case. 
Wishing to put up rather a largish bed on or about the 20th of 
January, to my surprise the dung got under cover three weeks 
previously has proved too far decomposed. Having spawned the 
bed on the ?8th, at all risk of a crop, I find that the heat is now 
(the 6th of February) quite gone. It will, under those unforeseen 
difficulties, be most acceptable to have the opinion of some more 
successful cultivator, through your columns, to know what is 
to be done. I think I hear some one say, “Why, of course, 
make another bed.” That is all right where the means of labour 
and expense are not thought of, but I must try for a crop: it 
is economy that is wanted here, and crops besides. I may 
mention that the Mushroom-liouse alluded to is simply a back 
shed with a flue on one side, the bed is on the floor 15 feet long, 
5 feet wide, and tapers up to a round crown about 2 feet high. 
—Alpha. 
[We should desire nothing better for a Mushroom-house than 
such a shed as you mention with a flue on one side. We pre¬ 
sume that the bed is in the middle, as it rounds off in the 
middle. It would have been as easily managed if built flat, or 
with a slope from back to front. The easiest mode to set the 
spawn working, will be to throw some long litter together 
until it heats a little, and then cover your bed with it from six 
to nine inches deep, until you find the surface of the bed as warm 
as new milk, when you can reduce the covering. In cold weather 
put a little heat in your flue besides. If this is inconvenient, 
heat the shed to 65° or 70° by the flue until you perceive the 
Mushrooms coming, and then gradually reduce the heat to from 
56° to 60°. By either of these modes you will succeed, if the 
spawn is still sound and [the materials are all right. If the 
spawn is gone, turn the bed over, and add a few bushels of fresh 
material and spawn again.] 
THE CONNECTION OF THE SCIENCES. 
ASTRONOMY, MAGNETISM, METEOROLOGY, AND THE 
CULTIVATION OP THE SOIL. 
We have discovered that electrical undulations are established 
upon the surface of the earth by the action of the solar rays, and 
that they circulate from east to west, varying in their intensity, 
with the varying position of the sun, relatively to the place of 
observation. 
That fine old Swedish philosopher, Oersted, proved the con¬ 
nection of magnetism and ordinary current electricity, and 
demonstrated that all magnetic phenomena take place at right 
angles to such electrical paths. Thus we know now that the 
magnet (the compass-needle) points to the north and south, 
because the electrical circulation is from the east to the west; 
magnetism and electricity being always at right angles to each 
other. There is a continual variation in th & force or intensity of 
the earth’s magnetism ; these variations—hourly, daily, monthly, 
and yearly—observing a certain degree of regularity, and ex¬ 
hibiting a peculiar dependence upon the relative positions of 
the earth and sun. 
Since every variation in the magnetic force of the earth pro¬ 
duces some disturbance in the magnetic needle, it was important 
to determine with exactness the laws by which these variations 
were regulated. As the commerce of the world is materially 
concerned in the perfect appreciation of all that affects the 
mariner’s compass, the great nations of Europe and America com¬ 
bined to establish magnetic observatories in all parts of the globe. 
Some mighty and mysterious power influences the earth’s 
electricity, and this is made known to man by the tremor of a 
magnetised bar. The intelligent observer solicits Nature to 
reveal the secret of this; and after long and patient prayerful 
working, an answer is given—that answer telling us that the 
phenomena of magnetism, as manifested on this planet, is the 
continuation of a development of physical force, dependant upon 
changes in the form of matter which occur in the sun. 
The sun’s brightness depends upon a gaseous self-luminous 
envelope—to which Avago gave the name of the Photosphere. 
This envelope is subject to peculiar disturbances, which are in¬ 
dicated to us by the formation of dark spots. These spots have 
been the subjects of observation since 1612, when Galileo made 
some important observations on them. Sir William Herschel, 
in 1801, published a remarkable paper on these spots, and 
endeavoured to show that there was some connection between 
the number of spots seen in any given year on the sun’s disc, 
with the price of corn in the English markets. But Hofrath 
Schwabe, of Dessau, has given us the most reliable informa¬ 
tion respecting these spots. During the long space of thirty 
years he has often examined the sun’s disc for upwards of 
300 days in each year. The tables which Schwabe has published 
leave no room to doubt that the solar spots occur in cycles of 
about ten years; the smallest number seen in any one year being 
thirty-three, the largest number being 333. Five years are ex¬ 
pended in advancing from the minimum to the maximum num¬ 
ber, and five years again descending to the minimum. 
Schwabe writes:—“Ido not believe that the spots on the 
sun have an influence on the temperature of the yearbut 
he could examine only the results of a limited area. The en¬ 
larged observations of Dove, who was supplied with returns 
from every part of the world, go to show that there is a con¬ 
nection between the variations of the mean annual temperature 
of the whole earth and the production of solar spots. We have 
not, however, now to deal with heat, but magnetism. All the 
observations made at the magnetic observatories of the world are 
returned to General Sabine, and carefully reduced, by a staff of 
engineers, under his direction, at Woolwich. The result of the 
most careful examination has been the announcement of the 
astounding fact—that the periodical inequality of the earth’s 
magnetic force has its opposite phases of maximum and mini¬ 
mum separated by an interval of five years, of which the cycle 
may be conceived to include about ten of our solar years. 
The regularity with which the alternations of increase and 
decrease have been traced by Schwabe, in his observations of 
the solar spots, is found to occur in the earth’s magnetism. 
“ The coincidence,” says General Sabine, “ as far as we are yet 
able to discover, is absolute ; the duration of the period is the 
same, and the epochs of maximum and minimum fall in both 
cases in the same years.” 
The periodicity of cold winters is a subject which has attracted 
the attention of M. E. Renou. He fancies that he has discovered 
that they return in groups of five or six, in a cycle of about forty- 
one years, alternating with corresponding groups of mild winters. 
He brings forward a large number of observations of the tempe¬ 
ratures of different months, ranging from about 1700 to the pre¬ 
sent year, in support of Iris proposition, and ascribes the singular 
period of recurrence to the same cause which governs the period 
of maxima and minima of solar spot.s. He calculates that we 
are now in the period of severe winters—the present one has 
been very severe. A warm summer never follows a very cold 
winter, and from that and other considerations he concludes 
that the summer of 1861 will not be a very fine one. It will 
not be quite so cold as the last, but will be at least 2° below the 
| average mean temperature of summer. M. Renou classifies 
summers accordimg to their temperature in the following way:— 
A mean temperature of 68^° Fahrenheit he calls “ very warm 
one of 67 0 is “ good 65° is “mean.” Below this temperature 
come the bad summers, 63° being “bad,” 611° “ very cold,” and 
59|-° “ exceptionalwhich latter temperature has only been 
reached in the winter of 1816. We may therefore expect that 
next summer may have an average temperature of 63°, and will, 
consequently, be classed amongst the “ bad.” The month of 
May, whose mean temperature varies from 55° to 59°, is this 
year to be 57°.— (The London Review.) 
ROYAL HORTICULTURAL SOCIETY. 
Fruit Committee.—A Meeting of the Fruit Committee was 
held in the new Hall of the Society at Kensington Gore, on 
Tuesday the 12th inst., Mr. Edmonds in the chair. The fol¬ 
lowing presentations to the Garden were announced :— 
H. Pownall, Esq., F.R.H.S.—Seeds of Ajaco, or Waran, the 
