FA I 
proper season. The position of these fungi 
led him to imagine that the progressive in- 
crease from a central point was the proba- 
ble mode of formation of the ring : hence 
he conjectured that the soil, which had 
once contributed to the support of the 
fungi, might be so exhausted of some pecu- 
liar pabulum necessary for their production 
as to be rendered incapable of producing a 
second crop. The second years crop would, 
if this theory be just, appear in a small ring 
surrounding the original centre of vegeta- 
tion, and at every succeeding year the de- 
fect of nutriment on one side would neces- 
sarily cause the new roots to extend them- 
selves solely in the opposite direction, and 
would occasion the circle of fungi continu- 
ally to proceed, by an annual enlargement, 
from the centre outwards. An appearance 
of luxuriance of the grass would follow as 
a natural consequence, as the soil of an in- 
terior circle would always be enriched by 
the decayed roots of fungi of the year’s 
growth. This theory is supported by some 
observations of Dr. Withering ; and Dr. 
Wollaston says, by way of confirmation, 
that whenever two adjacent circles are 
found to interfere, they not only do not 
cross each other, but both circles are in- 
variably obliterated between the points 
of contact : the exhaustion occasioned by 
each obstructs the progress of the other, 
and both are starved. Phil. Trans. 1807, 
Part II. 
Though it cannot be doubted that most 
fairy rings, if not all of them, have consider- 
able relation to the running of a fungus ; 
there, nevertheless, seems reason to con- 
clude that electricity may likewise be con- 
cerned in their production. The electrical 
effect may relate to fairy rings of a different 
kind from those occasioned by the fungus, 
or it may have been antecedent to the pro- 
duction of the vegetable. It is a familiar 
effect in our experiments that the spark 
proceeding from a positive conductor breaks 
or radiates at about one third of its course, 
and strikes the receiving conductor by a 
central spark surrounded by other smaller 
ones. The concentric rings produced upon 
polished metallic surfaces by the strong ex- 
plosion of a battery, as first observed by 
Priestley, appears to be a fact of the same 
kind ; and the forked radiations of lightning 
are well known. The editor of this work 
related in the Phil. Journal, Vol. I, 4to. 
some events which happened in Kensington 
Gardens in June, 1781, when a very power- 
ful thunder storm passed over the western 
FAL 
extremitv of London. The explosions were 
very marked and distinct, and in many in- 
stances forked at the lower end, but never 
at the top ; from which it seems proper to 
conclude that the general mass of clouds, 
or, at least, that extremity which passed 
over London, was in the state called 
positive. 
Five days afterwards, upon visiting Ken- 
sington Gardens, it was observed, that 
every part of that extensive piece of ground 
shewed marks of the agency of the light- 
ning, chiefly by discolouration of the grass 
in zigzag streaks, some of which were 50 or 
60 yards in length. Instances of this super- 
ficial course of the lightning, along the 
ground, before it enters the earth, are suf- 
ficiently frequent. But the circumstance 
applicable to our present subject is, that 
five trees, out of a grove consisting of seven, 
had been struck by the lightning. Two of 
them, which stood on the outside to the 
westward, had holes torn in the ground, 
close to the trunk ; and round one of these 
trees was a space of six feet in diameter, in 
which the grass was very much scorched. 
Another tree on the west was surrounded 
by a faint ring of burnt or faded grass, 
which seemed to be occasioned by some 
earlier stroke, as the vegetation had began 
to shoot up again. Another tree, standing 
on the outside to the south, was surrounded 
by a ring of 12 feet diameter and 18 inches 
broad. Within the ring the grass was 
fresh ; but on the surface of the ring, the 
grass and the ground were much burned. To 
the eastward of the tree, upon the ring it- 
self, were two holes, in which the ground 
had the appearance of ashes. Another tree, 
on the east-side of the grove, had the half 
of a faint ring to the westward. And, 
lastly, a tree which stood in the middle was 
surrounded by a faint ring of 12 feet diame- 
ter, within which the grass was unhurt ; and 
to the westward, at the distance of about 
three feet from the inner ring, was part of 
another similar ring, of nearly the same ap- 
pearance j the verdure being unhurt in the 
interval between the rings. 
FALCQ, the falcon, in natural history, a 
genus of birds of the order Accipitres. 
Generic character : the bill hooked and co- 
vered at the base with a, cere ; head and 
neck covered with closely-set feathers j 
tongue bifid at the end ; nostrils placed in 
the cere ; legs and feet scaly ; middle toe 
connected with the outermost by a strong 
membrane as far as tlie first joint ; claws 
large, much hooked, and very sharp ; the 
