1852. 
THE CULTIVATOR 
85 
chanics. Let us develop the principle upon which it acts. 
The earth is a large body, always charged with electrici¬ 
ty. Some have called it a generating battery. The at- 
mospere, and its vapors or clouds, is also a large body of 
matter always charged with electricity. But, owing to 
their different densities and compositions, these two bo¬ 
dies are always in different states of electrical condition. 
Sometimes the earth is more highly charged than the at¬ 
mosphere; but this is rare. Very often the atmosphere 
is more highly charged than the earth. Whenever either 
of these relations exists, there must necessarily be a non¬ 
conducting medium between the earth and the atmos¬ 
phere, or at least between the clouds and the earth, in 
the form of a stratum of nearly perfect anhydrous or 
dry atmosphere. Now, to equalise the electricity of the 
earth and the atmosphere, we have only to form a medi¬ 
um, through or over which the surplus electricity of the 
one may pass to the other. Doctor Franklin discovered 
how this might be effected. He raised a simple 
kite, armed with metalic points, and fastened to the earth 
by a wire. This brought the lightning from the clouds. 
This disarmed the clouds of their lightning. The metal 
of*the kite attracted the electricity of the cloud, the 
sharp points divided its current, so that it passed down 
the wire harmlessly. This w r as the first lightning rod, 
and illustrates the principle upon which it acts, viz: a 
continuous metalic medium from the earth to the cloud, 
or near it. Now, a perfect lightning rod must, therefore, 
be connected with the earth perfectly , and ascend as near 
as may be to the cloud, with a perfectly sharp point . A 
perfect connection with the earth can be effected by sink¬ 
ing the lower end of the rod to a depth that will ensure 
perfect and perpetual moisture. In some situations ten 
or fifteen feet deep will be required, in others four or five 
will be sufficient, owing to the different constituents of 
the earth at the place. It would never be safe to allow 
the lower end of a rod to rest in a sand bed; that must 
be passed through, though an hundred feet were pene¬ 
trated. When a situation of permanent and perpetual 
moisture is obtained, that is the depth to sink the lower 
end. And even then, a few feet square of copper sheet¬ 
ing should be soldered to the end of the rod. Some re¬ 
quire a deposite of pulverised charcoal to be placed at 
the bottom, in which the end of the rod is to rest. I 
would recommend, if charcoal be used at all, which I do 
not consider necessary, that it be mixed intimately with 
the earth at the bottom. It will serve to retain moisture 
in very dry seasons. The rod must be a single continu¬ 
ous rod, of round iron, three-eights to half an ineh dia¬ 
meter. It must be so long that it will reach from its 
deep insertion in the earth to the highest point above the 
house at which it can be sustained. It should be carried 
up within six inches, not less than four inches, of the 
house, and must be supported by some non-conducting 
substance in the course of its ascent, such as horn or 
glass. It should not be placed near nails or spikes, that 
is, no nails or spikes should be in the house directly be¬ 
hind the rod. Its upper end must be brought to a per . 
fectly sharp point . This is of the utmost importance, 
because the sharper the point the more easily will the 
fluid be divided by it. In this connection it must be borne 
in mind that it is the division of the current by the sharp 
point that prevents the shock; and that it is the presen¬ 
tation of an obtuse or blunt surface that produces it. 
Bear in mind, also, that it is the interruption of the cur¬ 
rent in all cases of electricity, that causes shocks. The 
sharp point avoids this, and hence, as has been shown in 
previous remarks, the heaviest charged Leyden jar, may 
be discharged by an infant with the point of a pin. And 
the sharper the point, the more perfect will be the dis¬ 
charge insensibly. To ensure this the point should be 
composed of platinum , on which metal the atmosphere 
has no effect. A cap of thin sheet platinum an inch or 
two long, drawn to a point, and soldered upon the iron 
rod, is sufficient. 
The old fashioned method of connecting several rods 
by a kind of hook and eye connection, is all wrong. 
Rust may and certainly will interfere to break the con¬ 
nection,—for it must be borne in mind that the oxyde 
of any metal (rust,) is a non-conductor of electricity. 
The whole rod must be made of one continuous rod of 
iron. This may be effected by perfectly welding the 
several pieces together, till you have the length required. 
In its connections for support to the house nothing but 
perfect non-conducting materials should be used. Clamps 
of wood with a section of horn or a ring of glass for the 
rod to pass through, are good contrivances. The higher 
the point of the rod is elevated above the highest part 
of the house, the more protection will be afforded. From 
casual shafts of lightning it is calculated that an eleva¬ 
tion of the point, four feet above the highest part of the 
house, will protect the house to the distance of eight feet 
each way, and that an elevation of eight feet will protect 
it to a distance of sixteen feet each w T ay. The rule should 
be however to elevate the point of the rod as high as it 
can be supported against the wind, for the higher it is 
the more protection it will afford. Let me once more 
caution against jointed rods and placing the rod opposite 
nails or spikes or any metalic substance, as these may 
attract the current from the rod. I would also caution 
against branch rods; that is, several rods above leading 
to a single rod below; and also against horizontal rods, 
running a distance along the roof or top of a house or 
tower, to the perpendicular stem;—its nature is to de¬ 
scend to the earth, and the horizontal rod affords an un¬ 
natural medium; they may pass over a nail or spike 
which would be very likely to attract the current and 
discharge it in the house. The rod may be painted black 
or left without paint at the option of the builder. It 
makes no difference. 
A word as to the nature of electricity. Many if not 
most people suppose that lightning is fire , of course that 
it is hot. This is not so; it is cold, or of the temperature 
of the surrounding atmosphere. But it is matter, com¬ 
monly called a fluid, and by its rapid passage through 
the air produces the appearance of fire in the atmosphere , 
by its friction, and in passing over wood or metal, ignites 
the one and melts or fuses the other by its friction 
merely. Franklin did not draw fire from heaven, as he 
is generally credited with having done, but he drew down 
a current of electricity, in a cool state, and did it so 
coolly that he did not even burn his fingers with it. How 
often do we see a green tree that has been struck by 
lightning, one side of it exhibiting the track of the fluid 
shivered into splinters. A dry tree is often set on fire 
by the friction. A barn is also set on fire by the fric¬ 
tion ; and nails and other metalic substances are fused; 
but still the fluid itself is cold. G. B. Smith. Balti 
more , Dec . 1851. 
Dairy Business on the Western Prairies. 
Eds. Cultivator —Whilst canvassing the fertile 
plains of Illinois and Iowa, in the pursuit of agricultural 
information, no branch of farming received greater at¬ 
tention than the management of the dairy. Some very 
unexpected developments were strongly presented to no¬ 
tice, all of which were highly favorable to the profitable 
prosecution of the dairy business on the prairies; and for 
the benefit of the patrons of the Cultivator, a plain prac¬ 
tical digest of the subject will be prepared for this and 
future numbers, in the hope that it will be the means of 
attracting public attention to a great interest, which has 
been comparatively overlooked by those who patronise 
the agricultural literature of the Union. 
In the principal cheese districts of New-York and Ohio, 
the value of freehold property has been for the last fif¬ 
teen years, gradually on the increase, until it has at last 
reached a point beyond which it cannot advance unless 
the products of the dairy obtain a corresponding increas¬ 
ed value; which result will scarcely happen so long as an 
abundance of cheap and fertile western lands are in the 
market. The value of land adapted for the dairy busi¬ 
ness, on the upper branches of the Mohawk, may be ra* 
