It was probably about 40 or 50 years ago when I read an absolutely riveting short story (possibly in a Gollancz sci-fi anthology) about a man who has a strange time portal open up near the ceiling in his house. He hears the sounds of a battle going on several times and later tries to communicate with the people on the other side of the portal. I don't remember much more about it or how it actually ended but I have always remembered it and would like to read it again.
I must have read this story during the mid or late 1960s. I recall that the man concerned somehow managed to work out that the noises he could hear were from one of the battles fought during the Crusades in the Holy Land. He heard loud shouting and screaming, the clash of blades, galloping hooves, neighing horses and other sounds of medieval conflict. I have a vague idea that a severed arm may have dropped through the portal at one time - but this may just be my vivid imagination running riot.
I also seem to remember that the portal only opened up for a few minutes each day and that he eventually tried to throw a paper message of some sort through the opening. I can't remember if he received a reply!
My father was a great science-fiction reader and I often read the books he borrowed from our local library including many of the yellow-jacketed Gollancz collections of short stories. I have done quite a lot of internet research regarding the contents of Gollancz anthologies and short story collections but have drawn a complete blank so far.