They were fortunate enough to secure their first practice and training in a local engineering office in the home town of Gridley.

Then, with vastly more courage than training, Tom and Harry went forth into the world to stand or fall as engineers.
Their first experiences are told in the opening volume of this series, "_The Young Engineers In Colorado_." Joining a western engineering force as "cub" engineers, at first the laughing-stock of the older engineers on the staff of a new railroad then building in Colorado, the two boys did their best to make good.

How well they succeeded is known to readers of that volume.

Their adventures in the Rocky Mountains were truly astounding; some of them, especially those with "Bad Pete," a braggart and scoundrel of the old school, were sometimes mirth-provoking and sometimes tragic.

Other adventures were vastly more serious.