Clarence Young was a house pseudonym used by the Stratemeyer Syndicate for series of books for boys, the most well-known being the "Motor Boys" series.
The Motor Boys were the heroes of a popular series of adventure books for boys at the turn of the 20th century issued by the Stratemeyer Syndicate under the pseudonym of Clarence Young. This series was published by Cupples & Leon and was issued with dustjackets and glossy frontispiece. Howard Garis (author of the Uncle Wiggly stories) wrote many, if not all, of these stories. NOTE: The name of their boat ( Dartaway) is also the name of the plane mentioned in The Rover Boys In The Air (1912).
The following series were published under the name Clarence Young:
Jack Ranger-6 volumes (1907-1911)
Motor Boys--22 volumes (1906-1924)--The first ten were illustrated by Charles Nuttall--Volumes 1, 2, and 8 ghostwritten by Howard R. Garis
Racer Boys-6 volumes (1912-1914)
The pseudonym "Clarence Young" was also used by Edward Stratemeyer for a few football stories published in turn of the century boys magazines.
summary by wikipedia.org