The Young Isambard series is stuffed full of references to the science of the period - below are just a few examples:
The Thames Tunnel
When we first meet Young Isambard he is working as an apprentice engineer for his father, Marc Brunel. Marc's latest project had been inspired by the way that the "sea-worm" burrows through solid wood, and the two Brunels began work on a new tunneling system which eventually would enable them to build the first tunnel underneath a navigable river.
The Thames Tunnel is being used to this day by trains crossing London and the principles that the Brunels pioneered are still being used in the construction of some of the biggest tunnels in the world.
Marc Brunel's "Tunnelling Sheild" in action
Isambard testing the riverbed using a diving bell
The Diving Bell
When Isambard's friends pile back to his place, they find a rather strange object on Isambard's bed that William manages to stuck on his head.
That object was a diver's helmet which became commonlplace later in the 19th century. But in fact the Brunel's preferred method of submarine activity was enabled by the diving bell, which you can read all about here in an article (which mentions Michael Faraday helping out - showing that Isamabrd and Michael did become buddies just as Mrs Faraday predicted).
A copper diving helmet which became popular later in the 19th century
Telegraph
Although the first commercial telegraph was by Cooke and Wheatstone following their English patent of 10 June 1837, in the book I have imagined that Dr Thomas Beddoes and James Faraday (Michael Faraday's father) had created an early prototype. There is a pretty good explanation of how it might have worked in Chapter 31 of Book#1.
Ironically, one of Isambard's great steamships, SS Great Eastern, would end its career laying telegraph cables in the ocean, being one of the few vessels large enough to carry the huge drums of cable required to cross the Atlantic.
<<< The Faraday / Beddoes telegraph machine (as described in Chapter 31)
Printing Telegraph from circa 1880, designed by George May Phelps >>>
The Hydrogen Balloon
Following Robert Boyle's Boyle's Law which had been published in 1662, and Henry Cavendish's 1766 work on hydrogen, Joseph Black proposed that if the gaseous element filled a balloon, the inflated object could rise up into the air. In France Jacques Charles, whose study of gases led to his namesake law of volumes, designed a balloon, and the Robert brothers constructed a lightweight, airtight gas bag which they used to effect the first manned balloon flight.
(In case you are wondering, the hydrogen was generated by adding a strong acid (eg sulphuric) to iron filings which reacted to produce hydrogen and iron sulphate.)
The technology they developed helped Vincenzo Lunardi become the first man to fly in England (and then Scotland). However, it is unlikely that Lunardi ever met Isambard in real life as Lunardi died in 1806, the year of Isambard's birth.
Internal Combustion Engine
When Isambard and Vincenzo Lunardi crash their balloon into a tree, they are saved by the redoubtable Mrs Faraday, who arrives in a popping and wheezing "wheeled chair". The engine popwering the chair is borrowed from the de Rivaz engine, which used hydrogen to fire a weight up a rail, so that the weight could then be used to drive the wheels...
The de Rivaz engine was a pioneering reciprocating engine designed and developed from 1804 by the Franco-Swiss inventor Isaac de Rivaz. The engine has a claim to be the world's first internal combustion engine and contained some features of modern engines including spark ignition and the use of hydrogen gas as a fuel.
The explosion drove the piston freely up the vertically mounted cylinder, storing the energy by lifting the heavy piston to an elevated position. The piston returned under its own weight and engaged a ratchet that connected the piston rod to a pulley. This pulley was in turn attached to a drum around which a rope was wound. The rope's other end was attached to a second drum on the charette's front wheels. The weight of the piston during its return down the cylinder was enough to turn the drums and move the charette.
The Solar Concentrator
In the book, Isambard meets Thomas Young who, in real life, made so many discoveries that he has since been referred to as "the last man who knew everything"! So it's not too improbable to expect that he would have known how to boil a pot of coffee using a solar concentrator as he does in Chapter 37 of Book#1.
A Solar Concentrator is a device that focus the sun's rays onto a smaller area to increse the energy density - this technology is being used today to focus the sun's rays to drive a heat engine (usually a steam turbine) connected to an electrical power generator.