The Boy Mechanic series continued after the publication of the initial book in 1913. There were at least four volumes of collected projects by 1936. Volumes 1 and 2 are available at the Internet Archive.
Fun fact: In the first volume, the words "nitric acid" and "sulphuric acid" appear together in four different articles.
I have learned that Wikipedia has no entry for its author, Henry Haven Windsor (13 November 1859 – 11 May 1924). Since the guy founded Popular Mechanics and its publishing empire, which has persisted for 107 years so far, you'd think he would be notable enough to warrant an entry. The magazine itself doesn't have much of an entry.
Since he lived to the age of 65, I presume Mr. Windsor was careful about mixing his acids, leaping off the barn roof in homemade gliders, etc.
I tinker with Wikipedia sometimes, but have never started an article and have not acquired the skills to do so. For anyone who might, here are some useful links.
Nice 1985 article from American Hertiage Invention and Technology:
1922 bio from the Press Club of Chicago:
Note that this is in the public domain, so the photo could be used to illustrate a Wikipedia article. (Link to high-resolution version.)
Wayne Whittaker, then Assistant Managing Editor, wrote a fantastic account of the magazine's history and operation for its 50th anniversary in 1952:
The history has been rehashed for other anniversaries:
In 1977: http://books.google.com/books?id=LOIDAAAAMBAJ&pg=PA72
In 2002: http://books.google.com/books?id=AtEDAAAAMBAJ&pg=PA95
HHW was succeeded as editor by his son, Henry Haven Windsor, Jr. The Windsor House (HH junior's place in Winnetka):
A different Windsor House on the Grinnell campus, celebrating the father of HHW:
Find A Grave lists his burial site:
Certainly a family worth celebrating. They cast a long shadow on the American technoculture.