47195    A long, low moan, indescribably sad, swept over the moor.

47196    It filled the whole air, and yet it was impossible to say whence it came.

47197    From a dull murmur it swelled into a deep roar and then sank back into a melancholy, throbbing murmur once again.

47198    Stapleton looked at me with a curious expression on his face.

47199    'Queer place, the moor!' said he.

47200    'But what is it?'

47201    'The peasants say it is the Hound of the Baskervilles calling for its prey.

47202    I've heard it once or twice before, but never quite so loud.'

47203    I looked round, with a chill of fear in my heart, at the huge swelling plain, mottled with the green patches of rushes.

47204    Nothing stirred over the vast expanse save a pair of ravens, which croaked loudly from a tor behind us.

47205    'You are an educated man.

47206    You don't believe such nonsense as that?' said I.

47207    'What do you think is the cause of so strange a sound?'

47208    'Bogs make queer noises sometimes.

47209    It's the mud settling, or the water rising, or something.'