Gideon the Cutpurse by Linda Buckley-Archer

Simon and Shuster
It's such a relief to read something in the third person. No teenage angst here, but solid adventure, set in the past with a time travel milieu, when two teens find themselves transported back to the eighteenth century after an accident in Kate's father's laboratory.
The two go on a search for a way back to the present, but their every effort is thwarted by the lack of modern comforts, travel in particular.

When they wake after the accident in the lab, they are found by Gideon, who helps them to his place of employment where they are given a warm welcome. With the excuse that their clothes were stolen by a highwayman, the lady of the house gives them clothing, although their feet are too big to fit any shoes they have. The body odour, clothing and especially the food they are offered to eat, all come as a huge shock to the pair, but they must put up with it until they find the man who has run off with the machine.

Tying their future with Gideon, they are all after the Tar Man, the scoundrel responsible for the theft of the machine and their journey takes them to London.  The story toggles cleverly between the families searching for their children, and the Police as they try to uncover the mystery, gaining no help from the family that knows what has happened and the children in the eighteenth century. It's all exciting and involved, riveting and so well written, you want to read more when it ends. And luckily there is a sequel.
Fran Knight