This book is an associational item, for the growing numbers of Praed Street Irregulars, for whom Solar Pons has proved to be an entertaining latterday Sherlock Holmes. Here are the marginal writings concerning the beginnings of Solar Pons—the sources of the tales —Dr. Parker's background—the favorite pastiches of some readers and critics.

Here also is a rich source of material about life at 7B, Praed Street—From the Notebooks of Dr. Lyndon Parker—in which we learn something of Solar Pons's inductive methods and certain minor cases brought to Pons's attention—the Park Lane housebreaking affair, the Morris will fraud, the Merstham Tunnel murder, the Foster assault, and, longest of all, The Adventure of the Bookseller's Clerk, a lesser adventure nowhere else published.