Show water hole Is dry by day A curious form of water hole le IJ la folind in the deserts of western aus dry by day but yielding no abundant supply of water by night the flow of water Is pre preceded ceded by byl eird hissing and find sounds of rushing air on examining one it was found that the water supply occurred in 4 a long narrow trench at the bottom 0 of which was a thin plate of gneiss species of rock arranged in lay layers erso cavity from the main separated by a beneath apparently th the rock mass ti heat of the day causes tills this plate to expand in the form of a depress depression lono in which the water rater retreats when forcel I 1 iti cools and contracts at fit night it force first air and then water rater back into th the trench i |