112 NOTES.—ORIGINAL AND SELECTED.
Cracking Noise in Roofing-Slates at Hale End.—
Being in the garden here between 7 and 7.30 on the evening of
the 10th inst. (April 1917), I became aware of curious noises
apparently emanating from the house, but was not able at first
to locate them exactly. After listening carefully and moving
to various positions in the garden, I at last decided that they
came from the roofs of my own and neighbouring houses.
The noises sounded like single large hailstones striking the
slates at irregular intervals. They could be heard easily about
150 feet away from the roof and 200 feet or more from those of
neighbouring houses. They might also be likened to the sound
made by giving a large loose slate held in the hand single sharp
taps with the end of a lead pencil or piece of firewood, and gave
one the impression that the slates were cracking one by one at
intervals of a minute or two.
There had been a sharp and thick snowstorm between 6.30
and 7, and there was a good deal of snow lying about in a thin
layer. The sky was ail-but cloudless and the temperature
decidedly lowered by the snowstorm.
The noises reminded me also of the sharp cracks emitted by
furniture when the weather suddenly changes from dry to damp,
and I concluded that they probably had a similar cause; not,
in this case, a change from damp to dry or vice versa, but a rapid
change in temperature. If this could produce a sudden shrinkage
of each slate, not simultaneously, and cause it thereby to grate,
so to speak, against the one adjacent to it or against the wood-
work of the roof, the hollow space beneath the latter might act
as an intensifier of the sound and so render it very audible.
Whatever may be the explanation, I shall be very interested
if anyone can furnish it, as I have never to my knowledge noticed
such a phenomenon before.—C. Nicholson, Hale End, Chingford.
Woodcock at Terling.—On Monday morning, the 9th
April, I was walking through Sandy Wood, Terling, when a
couple of woodcock rose immediately under my feet. They
flew about 50-100 yards only and dropped again in the
underwood. I have never before flushed a couple of woodcock
so late in the year. They were evidently a pair mating and
will probably nest in the neighbourhood.—J. Mackworth
Wood, M.I.C.E.