A delightful little book

Morning, Noon, and Night: A Teacher's Diary, by Ruth M. Twiss. Smithtown, N.Y. (11787): Exposition Press. $5.50.

This delightful little book won't take an hour to read. But you'll get much more than an hour of pleasure.

Miss Twiss was a business education teacher for more than 25 years in a city school and kept a diary.

She's concerned that teachers today aren't getting the credit they deserve for all the hard work they do, for their dedication to their profession, for their genuine concern for the youngsters they teach.

And so she's taken from her diary some direct quotes, providing readers with heartwarming stories exemplifying gently, but persuasively, what good teaching is all about.

There are those, particularly teachers in schools where the population is ever changing and where there is little collegiality among the staff, who might charge Miss Twiss with oversimplifying or of being highly selective in her recollections.

But the total impact of the little book is to remind us all that teaching is a ''Morning, Noon, and Night'' experience - one with many challenges, but deep rewards.