He just said-- 'Well don't be all day about it,' for he is a kind-hearted boy and can make allowances.

So Denny took off his boots and went into the pool.
'Oh, it's ripping!' he said.

'You ought to come in.' 'It looks beastly muddy,' said his tolerating leader.
'It is a bit,' Denny said, 'but the mud's just as cool as the water, and so soft, it squeezes between your toes quite different to boots.' And so he splashed about, and kept asking Oswald to come along in.
But some unseen influence prevented Oswald doing this; or it may have been because both his bootlaces were in hard knots.
Oswald had cause to bless the unseen influence, or the bootlaces, or whatever it was.
Denny had got to the middle of the pool, and he was splashing about, and getting his clothes very wet indeed, and altogether you would have thought his was a most envious and happy state.

But alas! the brightest cloud had a waterproof lining.

He was just saying-- 'You are a silly, Oswald.