They rowed round to the front of the queer little structure.

A man from inside held out his hand and helped them up.

Another young man, with books piled on the floor by his side, was making some calculations at a table.

Almost the whole of the opening of the place was taken up by what seemed to be a queer medley of telescopes and lenses pointing different ways.

Sir Meyville beamed upon them as he hastily turned a handle.
"Now," he promised, "you shall see what no one has ever seen before.
See, I point that arrow at that spot, about fifty yards out.