The House of Arden by Edith Nesbit

"To Richard Arden! " shouted the Mouldiwarp of Arden as it leaped on the hour hand of the pearl and ivory clock. And then the hands went round far too fast for speech to be possible. When the clock stopped, which it did quite suddenly, Edred caught his breath and shouted, "To my daddy! " at the top of his voice. And the hands began to move again so quickly that neither of the children had time to see where they had stopped. They just saw that they were in a room, and that the Mouldiwarp, who seemed suddenly to have grown to the size of an enormous Polar bear, leaned over the edge of the clock and caught at something with a paw a foot long. And then someone called out something that they couldn't hear, and almost at once the clock stopped, and they saw something climb off the clock. And the clock was in the cave again. And there was Cousin Richard in quite different clothes from those he had worn at King Henry the Eighth's maying.

They were the kind of clothes Edred had worn in Boney's time, and the cave was just as it had been then, with kegs and bales, and the stream running through it.