•HS- 
AMERICAN AGRICULTURIST. 
LIGHTNING NODS. 
To the Editor of the American Agriculturist. 
I send you three new subscribers, and 
wish I could send you more, for I think your 
paper indispensible in my small farming. I 
am satisfied it has made me $25. Will you 
tell us in your next, if No. 1 wire will do for 
lightning rods, and if not why ? 
Yours Truly, 
Wm. Henry Maxwell. 
Jonesborough, East Tenn., October 2,1856. 
The above is given as a specimen of hun¬ 
dreds of encouraging letters received quite 
recently. Many put the profit derived from 
the paper at a still higher figure. 
We think No. 1 iron wire too small for a 
safe lightning rod. If of copper, it might 
do, but copper costs several times as much 
as iron, and it is therefore better to get iron 
of larger size. No. 1 wire is about five-six¬ 
teenths of an inch in diameter, or a little 
more than a quarter-inch. When a rod is 
well pointed and kept bright, it will usually 
draw off electricity from a cloud gradually , 
and generally one but half the size of No. 1, 
would suffice to conduct away the charge 
from a cloud. But a large, heavily charged 
cloud, moving rapidly, would be likely to fur¬ 
nish sufficient electricity to melt a small rod. 
We have several times melted a wire larger 
than a large knitting needle with the elec¬ 
tricity from an electrical apparatus of our 
own construction. Not only is there dan¬ 
ger that a small lightning rod will be melted, 
but, from its want of capacity to conduct to 
the earth all the electricity of a large cloud, 
a part of the charge is quite likely to di¬ 
verge from it and enter some part of the 
building. We have heard of such instances, 
and also of a building being set on fire by the 
red-hot molten iron of a small rod. 
We put up a rod upon our own dwelling in 
August last, which is constructed thus : A 
half-inch iron rod is made very point¬ 
ed at the upper end, and plated with silver 
from the point downwards about eight inches. 
A single point only is used, which stands 
over the center of the house and reaches 
twelve feet above the highest point of the 
roof or chimneys. No chimney is distant 
more than 14 feet from its base. Three 
small “ slanting ” wooden braces, touch the 
rod about five feet above the roof and pre¬ 
vent it from blowing over. It is bent at the 
base in a gradual curve—not a short angle 
which would make it a poorer conductor— 
and it is then carried along the roof and over 
the corner with another long curve, and 
thence down into the moist earth. The end 
is finally carried into a cistern, and termi¬ 
nates in the water at the bottom The rea¬ 
son for carrying it first into moist earth is to 
still have it in connection with the ground, 
if the cistern should chance to be dry. The 
supports on the roof and sides of the build¬ 
ing are glass thimbles clasped in an iron 
staple somewhat like the letter P. The 
necks of common junk bottles will answer 
very well for the glass thimbles. They may 
be held in wooden supports as well as in 
iron staples. 
A continous rod, with no joints from top to 
bottom, is much the best. If separate pieces 
are used they should be welded together, or 
at least well locked and twisted so as to fur¬ 
nish a good connection at the joints. Our 
own rod consists of several pieces which go 
together with screws. The connecting piece 
is an inch in diameter, three inches long, and 
hollow. The thread of the screw at either 
end is cut in different directions which per¬ 
mits joining the rods by simply turning the 
joining piece. This is a simple and perfect 
arrangement, and the rod can be taken down 
and put up in a few minutes. 
Many or few Points .—For a very large 
building, several points furnish a greater 
protection than one single rod. 
One side of a very compact cloud may pass 
near the corner of a building and discharge 
its electricity through it to the ground. In 
this case the single rod in the center of the 
building would be too distant to draw of the 
charge. In almost all cases, however, some 
part of the cloud will pass over a central rod. 
After considerable investigation of this sub¬ 
ject we think the plan we have adopted the 
cheapest, and sufficiently safe for any build¬ 
ing of ordinary dimensions. The main thing 
is to carry it sufficiently high. The rule 
generally laid down is, that the horizontal 
distance from the rod to any point to be pro¬ 
tected should not be greater than twice the 
hight of rod above that point. Thus: if a 
rod be erected 20 feet from the top of a chim¬ 
ney it should extend ten feet higher than the 
chimney. While about it, it is quite as well 
to make the proportional hight somewhat 
greater than this. —Ed. 
STONE WALLS-TO PREVENT THEIR FALLING 
IN WINTER. 
A correspondent asks, “ How shall we 
keep our stone walls from being thrown 
down by frost the coming winter 1” If 
properly built at first, there would be no 
danger of their falling; rather, we should 
say if properly placed they would not fall. 
They are displaced by the action of frost, not 
upon the walls nor upon the soil itself, but 
upon the water saturating the soil. Ail sol¬ 
id bodies contract more or less in cold 
weather, but in a stone wall or in dry earth, 
the contraction or change of bulk is not suf¬ 
ficient to displace even a loosely built wall. 
Water, on the contrary, expands largely in 
freezing. Eight barrels of water will yield 
nine barrels full of ice. Take a barrel three 
feet high, put into it 32 inches in depth of 
water, then allow it to freeze and the barrel 
will be just full. Precisely the same result 
would be obtained if 32 inches of a mixture 
of soil and water had been used instead of wa¬ 
ter only. But put in dry earth and the ex¬ 
pansion or increase of bulk will scarcely be 
perceptible. 
Just so the soil under a wall, when satur¬ 
ated with water, will expand an eighth of its 
bulk in freezing, and raise the wall by so 
much. If now one side thaws before or 
faster than the other, that side of the wall 
will settle down more rapidly, and the 
chances are that the whole will be displaced 
and perhaps tumbled down. 
The remedy is simple. Run a drain or 
3Q1 
ditch near the wall, deep enough to render 
the soil under it dry to as great a depth as 
the frost will penetrate, and unless very care¬ 
lessly built, there will be no danger of the 
stones tumbling down. 
It is better to erect a stone fence upon a 
ridge of dry land at first, than to dig a foun¬ 
dation in a wet surface. If the latter course 
is pursued, the damp earth upon either side 
will expand and contract unequally, and 
throw down the best constructed stone wall. 
The same is the case with posts set in a 
wet soil. Freezing elevates the frozen earth, 
and as this is solid around the post it will 
raise it out of the unfrozen soil below, but 
it will not usually settle back again when 
thawing takes place. A few successive 
freezings and thawings will ultimately raise 
the posts entirely above the surface, when 
they will fall over. This can only be rem¬ 
edied by draining off the water. 
In the erection of foundation walls for 
buildings in wet ground, it has been recom¬ 
mended to build open spaces in them and 
set in perpendicular blocks of wood upon 
which the sills may rest, and to fill in around 
these with tan bark, gravel or coarse sand. 
This plan will answer a good purpose if the 
filling around the supporting blocks be kept 
dry, and not otherwise. —Ed. 
AN EXPERIMENT WITH A SALT MARSH. 
CAPITAL WELL INVESTED-A GOOD EXAMPLE. 
The communication of our correspondent 
‘Inquirer,’ in our last issue, opens a subject 
of great importance to our shore farmers. 
There are thousands of acres all along the 
coast, from Maine to Florida, bearing now 
nothing but poor salt hay that hardly pays 
for cutting, that might be brought into beau¬ 
tiful upland meadows, at a very small ex¬ 
pense. Almost every small creek or brook, 
emptying into the sea, is bordered by ex¬ 
tensive marshes near its mouth, that only 
wait for a little skill and capital to make 
them largely productive. These marshes, 
vary in extent from a few acres to several 
thousand, and in quality from a quagmire 
yielding only coarse flags, to a close smooth 
turf, yielding black marsh hay. They are 
for the most part perfectly level, and free 
from stones, and already so hard as to admit 
of driving a loaded team over them, in the 
summer. They are the kind of land adapted 
to the mowing machine, and in all efforts at 
reclaiming them, it should be kept in mind, 
that they are to be mowed by horse-power2 
We have just visited one of these mead¬ 
ows, reclaimed two years since, and which 
already has paid the whole expense of its 
improvement. Though the experiment has 
not been long enough to determine the prac¬ 
ticability of raising grain crops, and other 
matters of interest, still it demonstrates the 
economy of shutting off the sea water. 
Following the order of our correspondents 
enquiries, we will give a brief outline of our 
friend’s experiment. 
LOCATION. 
The meadow consists of thirty acres, and 
lies upon both sides of a little creek, empty¬ 
ing into one of our large navigable rivers, 
some five miles from its mouth. This creek 
breaks through a high ridge just before it 
