There are many interesting things
about a night in late summer and early
autumn, but few things that belong to it
are more exciting than the determination
of the temperature by the rapidity of the
chirping of the "crickets" as the little
green fellows that fiddle monotonously with
their wings are popularly called. That
measured, ceaseless "chirp, chirp, chirp"
is certainly quickened as the temperature
rises and slowed as it falls. I have seen
the scale of the thing in print somewhere,
and I doubt not that it is fairly familiar -
so many chirps for 75 degrees, so many for
70, so many for 60; and at 50 the chirping
is low and very slow indeed. One of the
recent nights the mercury stood at about
80 degrees, and the chirping was simply
fast and furious. I was the witness of a
curious little experiment in connection with
this phenomenon. One of the green insects
somehow got into a country dwelling-house
and took up his residence on a pair of lace
window curtains. There he chirped every
night, and never ceased when a bright light 
was brought close to him and a public ex-
hibition made of his method of fiddling with
his wings. As the air in the room became
heated during the day and did not for some
hours fall to so low a temperature as the
[one] out-of-doors, this indoor cricket was
bound by the rules of the game to chirp
much more rapidly than the crickets out
in the cool night air - and he did. His rate
was considerably quicker than theirs.
Moreover, when he felt the reflected heat
of the lamp he began to chirp still more
rapidly. This gave me an idea. As the
night was still and a lighted lamp could be
carried out-of-doors, I took the lamp and
went out to a wild cucumber vine, on which
several of the insects were chirping. I
held it underneath the vine; and as soon
as its warmth had permeated the air about
the vine, the two or three insects that were
there began chirping at a more rapid rate
than the insects about them. I have never
seen any scientific explanation of this phe-
nomenon. It is easy to understand that a
considerable degree of cold might make the
insects' wings torpid; but why a heat of
80 degrees should set them to chirping
more rapidly than the presumably agree-
able one of 75 degrees is a little hard to
understand.