Hopefully this will be helpful to people applying to study Engineering at a competitive University: my school didn't really have a clue what I could read as a help to applying to Cambridge.
In addition to the Gordon books from the below list I read "The Science of Superheroes" by Gresh and Weinberg which is quite interesting. Actually, any total over-analysis of ordinary or fictional things interests me.
New Science of Strong Materials - J.E. Gordon
Structures - J.E. Gordon
Cats' Paws and Catapults - Vogel
What Engineers Know and How They Know It - Vincenti
Flying Butresses, Entropy and O-Rings - Adams
Inverntion by Design - Petroski
How Things Work - Bloomfield
Advanced D&T - Norman, Cubitt, Urry, Whittaker
To Engineer is Human - Petroski
Remaking the World - Petroski
Why Buildings Fall Down - Levy and Salvadon
Why buildings stand up - Salvadon
Made To Measure - Ball
Small things considered - Petroski
Seven Wonders of the Industrial World - Cadbury
Backroom Boys - Spufford
Obviously not an exhaustive list, and it's pointless to read everything on it, but in an interview or personal statement it could give you an edge. "I'm really interested by entropy" is probably better than "I like maths, physics and railways".