A huge plastic ball appears on one side of each appealing double-spread photo here, with the added interest of a child (playing at the shore); an artist; a dog; a fire truck; or simply the foaming surf. Broad white margins on either side accommodate the reader's two hands--vividly labelled, as they hold the book, by the words ""left"" and ""right,"" printed in the ball's rainbow colors. Every aspect of this basic concept book is worked out with MacMillan's usual extraordinary care: many things in addition to the ball can be described as being at left or right; artfully, he controls his limited color scheme and contrives beautifully composed scenes that are virtually devoid of extraneous details. In all: a delightful means of reinforcing an essential concept. Notes on the photography and the participants.