Books #1 and 2 First Edition
This five volume series was
first introduced in 1912 with a two volume breeder set. The first
edition dust jackets for the first two titles that were published in
1912 list only the two Young Engineeer books:
The Young Engineers in Colorado
The Young Engineers in Arizona
But this jacket does not
absolutely indicate a first edition. Determining the true first edition
for the first two titles requires an analysis of the advertisements in
the back. The true first edition lists only three Automobile Girl books
whereas the later books list four Automobile Girl books.
Also the ad for the Young Engineers is different. The first edition
blurb is the same as the dust jacket blurb.
The first edition-second state blurb is different. It is the one that
is used in all subsequent Young Engineer ads.