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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 all-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 intensiher 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.IC.E. 
