1882.] 
AMERICAN AGRICULTURIST. 
61 
Nitrogen; taking the potatoes grown by 
mineral manures alone at 26 lbs., we find in 
those grown by Ammonia and minerals 66 
lbs., or an increase of 40 lbs. ; but as we sup¬ 
plied 85 lbs. in the manure, we have recov¬ 
ered something less than 50 per cent of the 
amount supplied, and this, too, under the in¬ 
fluence . of an unusually favorable season! 
Taking an average of seasons, it would be 
much nearer the truth to say that not more 
than one-third of the Nitrogen supplied is re¬ 
covered in the crop. Potatoes contain 25 per 
cent of dry matter in every 100 lbs. ; if we 
take a bushel to weigh 50 lbs., 8 bushels will 
weigh 400 lbs. ; which amount is equivalent 
to 100 lbs. of dry matter, and will contain 1 
lb. of Nitrogen. 
To obtain this 1 lb. of Nitrogen in the pro¬ 
duce, we find it necessary to apply 8 lbs. in 
the manure, and as the Nitrogen costs about 
25 cents per lb., this large difference between 
the amount supplied and that recovered be¬ 
comes a very serious consideration. 
I might further observe that as our experi¬ 
ments are conducted with more care and at¬ 
tention than could possibly be given to crops 
grown under the ordinary operations of agri¬ 
culture, I do not think it would be safe to 
reckon on a smaller loss than that which we 
have incurred, and the probability is that it 
might be much larger. 
The general conclusion to be drawn from 
these experiments, as well as from those upon 
root crops in general, such as turnips, man¬ 
gels, and sugar beet, is that they do not ob¬ 
tain their Nitrogen from the atmosphere; 
and that, when supplied with that substance, 
the amount recovered in the crop is very 
much less than that supplied in the manure. 
Clearing a Field of Sod. 
Mr. J. C. Nelson, Brown Co., Wis., having 
occasion to clear a field of its sod, proceeded 
in the following manner: The land was 
Fig. 1.—A HOME-MADE SOD CUTTER. 
plowed about three inches deep, and so that 
the sod was cut entirely free from the ground. 
A sod-cutter was made from a shovel-plow, 
by removing the shovel, and placing a bent 
timber below the beam and the standard. A 
slot was sawed in the horizontal portion of 
the timber, in which an iron plate was fasten¬ 
ed by means of bolts. The knife was made 
Fig. 2.—A SOD FORK. 
from an old 14-inch circular saw, with the 
teeth cut off and the edge ground sharp. The 
cutter, fig. 1, was drawn by a single horse, 
and in a direction at right angles to the fur¬ 
row slices, thus cutting the sods into square 
pieces of a suitable size to handle easily. A 
hay-fork was not adapted to this heavy pitch¬ 
ing, and a sod-fork or hook was made for the 
purpose. A piece of 3 1--inch cast steel, 8 
inches long, was ground to a sharp point and 
fastened in a long wooden handle, shown in 
figure 2. A bend in the tine near its inser¬ 
tion in the handle makes the sod-fork more 
convenient for the workman. 
A Talk with Farmers About the Weather. 
BY PROF. J. \y. CHECKERING, WASHINGTON, D. C. 
What can be foretold about the weather? 
Not guessed at, but predicted on some basis 
of reason, with a fair degree of certainty, say 
three or four chances to one. 
The desire and the attempt are very old. 
The Good Book speaks of those who, two 
thousand years ago, used to say at evening : 
“ It will be fair weather, for the sky is red ” ; 
or in the morning, “It will be foul weather 
to-day, for the sky is red and lowering.” 
And ever since then have there been, as 
now, plenty of weather prophets on a small 
scale, both on the sea-coast and in the inte¬ 
rior, sailors, farmers, and others, much in 
the open air, who have had considerable skill 
in discussing and interpreting weather indi¬ 
cations. Within the past 33 years, first the 
Smithsonian Institution, and now the Signal 
Service Division of the Army, have taken up 
the business on a large scale, publishing maps 
and sending out “ indications ” for the whole 
country two or three times a day. 
But with longer forecast, many people at¬ 
tach great importance to several “signs.” 
When the squirrels and the field-mice lay up 
abundant stores of nuts or grain; when the 
fur is heavier and the feathers thicker; when 
the beavers and the musquashes build higher 
dams and thicker huts, it is by many sup¬ 
posed not merely to indicate that it has been 
a favorable season, so that corn and nuts are 
more plenty, and easier to gather; the beasts 
and birds better fed so as to be able to make 
better fur and feathers ; the streams higher 
and the supply of material greater for the 
dam-builders, and the hut-makers, but in ad¬ 
dition to foretell an unusually severe winter. 
But alas ! these signs often fail, just as the 
wild geese have often started north in pre¬ 
mature warm weather, only to encounter 
heavy snow storms, and the ground-hog 
come to grief from trusting to his shadow. 
So, latterly, have arisen Vennor, Tice, and 
others, making themselves conspicuous by 
predictions of what the weather will be for 
the next month, or even a twelvemonth 
ahead; sometimes contenting themselves 
with general prophecies of hot weather with 
showers in July, and cold boisterous winds 
with occasional snows in December, which 
generally prove true, unless we happen to 
have a cool July or a mild December; and 
sometimes at a venture, hazarding specific 
guesses of extraordinary variations, seldom 
coming true, and generally needing to be 
amended and explained after the fact. Now 
what are we to believe in ? How much credit 
is to be given to these predictions, by the 
farmer who desires to be neither an old fogy 
nor a “greenhorn ” who is too easily hoaxed ? 
With regard to any prognostications as to 
the weather, one year, or one month, or one 
week ahead, he is to pay no more attention 
than he does to patent medicine advertise¬ 
ments, or agents for patent churns. Those 
who have longest and most carefully studied 
and recorded the weather, know best, that 
beyond two or three days, no predictions can 
be made possessing the slightest reliability. 
or that should be taken into account in mak¬ 
ing our plans. There may be lucky guesses, 
as there may be woful failures in guessing. 
Everybody has full liberty to guess what 
the weather will be at any time in the future. 
But when anybody undertakes to label his 
guesses for weeks or months ahead, “ predic¬ 
tions,” and to issue them as guides for the 
farmer, or the traveller, or the clothing dealer, 
he, in the language of Shakespeare, “ writes 
himself down an ass.” When he undertakes 
to get money for doing this, he shows him¬ 
self a swindler on a level with other quacks. 
But for one or two, or even three days 
ahead, the weather may be foretold, two- 
thirds of the titne with great certainty, the 
other third with more or less of doubt. And 
not only can this be done by the trained ob¬ 
server at the signal station, but it may be at¬ 
tempted with good success by any intelligent 
person who has access to the daily weather 
maps, or even to the full daily report. It 
would be a great gain to the community if 
our daily papers would give us these reports 
in full as they are sent out, instead of cut¬ 
ting them down to the mere “indications” 
for their own vicinity, even if they had to 
lessen the space given to horse races, base 
ball matches, dog fights, and police courts. 
The whole theory of foretelling changes in 
the weather, with the aid of the telegraph, is 
based upon the fact that our weather changes 
come, as a general rule, from the west and 
not from the east; that the great waves of 
barometric pressure, which we name high 
and low. and whose alternations produce our 
storms, move across our country from west 
to east, and almost never in the opposite di¬ 
rection, so that for our weather to-morrow, 
we look to see what it is to-day to the west 
of us, with very little interest as to what is 
going on toward the eastward. Thus in New 
England, a north-east snow-storm is often 
telegraphed as coming from the south-west, 
from New York, or even from Virginia, or 
the Carolinas, or even further South. 
The pressure of the atmosphere in the tem¬ 
perate zone varies about one pound per square 
inch, and is indicated by the barometer, 
varying from 29 inches (low) to 31 inches 
(high) as the extremes, the ordinary varia¬ 
tions being only about half as great. Now 
the storm-center is at or near the place of low 
barometer, where the pressure is least, the 
air from all sides rushing towards this with 
a rotary motion, which in very severe storms 
is named a cyclone. Sometimes, however, 
the areas of high and low barometer extend 
in long lines across the country from north 
to south, but moving from west to east, as in 
many of our “cold waves,” extending some¬ 
times from the Lakes to the Gulf. The great¬ 
est fall of rain or snow is usually a little in 
advance of the storm-center, while the ba¬ 
rometer is falling. When the center lias 
passed, the barometer begins to rise, and 
clearing weather may be expected, generally 
with north-west winds. 
These storm-centers, or “areas of low ba¬ 
rometer,” or “ low pressure,” oftenest make 
their appearance a little east of the Rocky 
Mountains, very often in Dakota, and then 
move with greater or less rapidity toward the 
Atlantic, generally due east. Occasionally a 
storm-center develops in Texas, and moves 
north-east. More rarely cyclones make their 
appearance in the West Indies, and follow 
along the course of the Gulf Stream, the outer 
