310 
large tree, than in the open field. A 
person in any exposed situation, on be- 
ing surprised by a thunder-storm, or 
whenever lightning is prevailing, should 
throw aside any iron implement, or metal 
of any kind, from his person ; and place 
himself in the vieinity, wizhin fifty yards, 
though not in contact, with any high tree 
or building. 
M. Lussac recommends that conduct- 
ing-rods should be much longer than 
they are commonly made, or else that 
we apply a greater number, so as to 
allow for the whole extent of a large 
edifice being brought within the pro- 
tecting influence of the rods. It is also 
necessary, that any lateral branches of 
rods, which connect the main or perpen- 
dicular rods together, should not be of 
a smaller diameter than the principal 
rods: otherwise, it would prevent a 
free passage of the fluid, and conse- 
quently endanger the building. 
M. Lussac considers, that a building 
of sixty feet in length would be suffi- 
ciently protected by a rod projecting 
fifteen, or eighteen feet above the roof ; 
or that the point of the rod protects a 
circle, whose diameter is about four 
times the height of the rod, from the 
roof of the edifice. It is, therefore, ob- 
vious, that a conductor whose point 
ascends from the middle of the roof 
of a large house, affords nearly as much 
protection as if a rod were erected at 
each end of the building,—provided the 
size of the central rod be sufficient to 
carry off the fluid instantaneously into 
the earth. It is, in all probability, only 
the want of sufficient extent of metallic 
surface for such instantaneous transit, 
which produces the intense heat accom- 
panying the passage of the electric fluid 
through a dwelling-house,—in many 
cases producing combustion, and heat- 
ing red-hot, or even melting bell-wires, 
keys, &c. 
It was proved, by some experiments 
on the best mode of protecting ships 
from the effects of lightning, made with 
a powerful machine a year or two back, 
by a gentleman of the name of Harris, 
that, if a communication be kept up by 
means of a metallic wire or chain, from 
the mast-head of a vessel, and through 
the bottom into the water, even if the 
chain be in immediate contact with 
gunpowder, or fulminating powder, no 
explosion takes place; but, on the con- 
trary, if there be any interruption to the 
circuit, by dividing or cutting off the 
wire or chain near its junction with the 
powder, an explosion always ensues : 
Query for the Smithfield Club.—Furnival’'s Inn. 
{May I, 
—thus distinctly proving, that the great 
elevation of temperature which the elec- 
trical discharge often produces, is the 
result of the electric matter being ob- 
structed in its passage into the earth, or 
water, as the case may be. 
M. Lussac satisfactorily shews, that 
it is of little importance whether the 
branches of a conductor extend at an 
oblique angle with the perpendicular 
rod, or even proceed horizontally along 
the roof or sides of a building, provided 
the communication be perfectly main- 
tained, and no other metallic matter 
afford a shorter route for the passage 
of the fluid into the earth. It is also 
advisable to have the top of a lightning- 
rod made of a conical form, terminating 
ina point, rather than to make them 
taper a considerable way down, as is 
usually the case. The top of the rod 
should also be made of copper or brass, 
by which it would be less liable to oxi- 
dation, and consequent destruction of 
its point. In situations where a rod 
might be considered injurious to the 
uniform appearance of a building, M. 
Lussac recommends a flat chain made 
of wire, which will be equally efficacious 
for the security of the edifice. —A, A. 
——=<—>_-— 
To the Editor of the Monthly Magazine. 
Sir: 
N the “ Varieties” of a late number 
of your increasingly valuable mis- 
cellany (No. 407, p. 171), I observe a 
short notice of the late anniversary 
of the Smithfield Cattle Club ; in which 
you very properly refer to its fundamen- 
tal principle of “ supplying the market 
with the cheapest and best meat.” Fol- 
lowing up the idea, will you allow me 
to ask the gentlemen attached to this 
club, whether the fattest is necessarily 
the best ?—whether fat —fat, and nothing 
but rat—is henceforth to satisfy the 
Meat-Eater, 
London, 7th April. 
rr 
To the Editor of the Monthly Magazine. 
Sir: 
AM informed, that the well-known 
building, called Furniyal’s Inn, de- 
rives its name from its having, hereto- 
fore, been the residence of the Lorps 
FurnNival. 
Perhaps, Sir, you will allow me, 
through your valuable miscellany, to ask 
an explanation of the office of Furnival. 
—Your’s, &c. Q. 
9th March. 
To 
