INTRODUCTION
as full of fun. When they go to New York City they have some strenuous times, and all prove their worth in more ways than one. Their father is in deep trouble and they aid him, and clear up quite a mystery.
Up to this writing, the sale on this line of books is but a trifle short of one million and a quarter copies! This is to me, of course, tremendously gratifying. Again, as in the past, I thank my many readers for their interest in what I have written for them, and I trust the perusal of my works will do them good.
Affectionately and sincerely yours,
Edward Stratemeyer
