in search of a long-lost storybook

[bassspine]

I'm seeking a book I read in the 1970's whose title I cannot remember.
It concerned some children who had discovered aliens living in Kew Gardens.They had feathers or leaves covering them and were in hiding.
I remember there being a feast which included a course consisting of a giant bowl of gerden peas covered in melting butter, eaten with ladles.

Can anyone shed any light on the title?

[RJBowman]

I don't recognize the book, but I'd like to add my own request.

I saw a book in an antique store in the mid 1980's, and have regretted not buying it ever since. It was a children's book, written in the 1920's, and told a story of children living 100 years in the future, which would be the 2020's.

The book had black ink illustrations of children flying using wings attached to their backs, reminiscent to Da Vinci's aircraft. There was a bit of dialog in which the children's mother tells them not to fly to far, and that she would radio them when dinner was ready.

I thought that the title contained the words "life in 100 years", but I could be mistaken. I have been unable to identify this book using any we sources.

If this book is familiar to anyone, please speak up.